diff --git a/src/ai/ai_gui.cpp b/src/ai/ai_gui.cpp
--- a/src/ai/ai_gui.cpp
+++ b/src/ai/ai_gui.cpp
@@ -978,7 +978,7 @@ struct AIDebugWindow : public QueryStrin
 
 					/* Check if the current line should be highlighted */
 					if (pos == this->highlight_row) {
-						GfxFillRect(r.left + 1, r.top + y, r.right - 1, r.top + y + this->resize.step_height - WD_PAR_VSEP_NORMAL, GREY_SCALE(0));
+						GfxFillRect(r.left + 1, r.top + y, r.right - 1, r.top + y + this->resize.step_height - WD_PAR_VSEP_NORMAL, PC_BLACK);
 						if (colour == TC_BLACK) colour = TC_WHITE; // Make black text readable by inverting it to white.
 					}
 
diff --git a/src/airport_gui.cpp b/src/airport_gui.cpp
--- a/src/airport_gui.cpp
+++ b/src/airport_gui.cpp
@@ -356,7 +356,7 @@ public:
 				for (uint i = this->vscroll->GetPosition(); this->vscroll->IsVisible(i) && i < AirportClass::GetCount(_selected_airport_class); i++) {
 					const AirportSpec *as = AirportClass::Get(_selected_airport_class, i);
 					if (!as->IsAvailable()) {
-						GfxFillRect(r.left + 1, y + 1, r.right - 1, y + this->line_height - 2, GREY_SCALE(0), FILLRECT_CHECKER);
+						GfxFillRect(r.left + 1, y + 1, r.right - 1, y + this->line_height - 2, PC_BLACK, FILLRECT_CHECKER);
 					}
 					DrawString(r.left + WD_MATRIX_LEFT, r.right + WD_MATRIX_RIGHT, y + WD_MATRIX_TOP, as->name, ((int)i == _selected_airport_index) ? TC_WHITE : TC_BLACK);
 					y += this->line_height;
diff --git a/src/company_gui.cpp b/src/company_gui.cpp
--- a/src/company_gui.cpp
+++ b/src/company_gui.cpp
@@ -209,7 +209,7 @@ static void DrawYearColumn(const Rect &r
 		if (et == INVALID_EXPENSES) {
 			Money cost = subtotal;
 			subtotal = 0;
-			GfxFillRect(r.left, y, r.right, y, GREY_SCALE(1));
+			GfxFillRect(r.left, y, r.right, y, PC_BLACK);
 			y += EXP_LINESPACE;
 			DrawPrice(cost, r.left, r.right, y);
 			y += FONT_HEIGHT_NORMAL + EXP_BLOCKSPACE;
@@ -222,7 +222,7 @@ static void DrawYearColumn(const Rect &r
 		}
 	}
 
-	GfxFillRect(r.left, y, r.right, y, GREY_SCALE(1));
+	GfxFillRect(r.left, y, r.right, y, PC_BLACK);
 	y += EXP_LINESPACE;
 	DrawPrice(sum, r.left, r.right, y);
 }
@@ -385,7 +385,7 @@ struct CompanyFinancesWindow : Window {
 			}
 
 			case CFW_LOAN_LINE:
-				GfxFillRect(r.left, r.top, r.right, r.top, GREY_SCALE(1));
+				GfxFillRect(r.left, r.top, r.right, r.top, PC_BLACK);
 				break;
 		}
 	}
diff --git a/src/console_gui.cpp b/src/console_gui.cpp
--- a/src/console_gui.cpp
+++ b/src/console_gui.cpp
@@ -204,7 +204,7 @@ struct IConsoleWindow : Window
 	{
 		const int right = this->width - 5;
 
-		GfxFillRect(0, 0, this->width - 1, this->height - 1, GREY_SCALE(0));
+		GfxFillRect(0, 0, this->width - 1, this->height - 1, PC_BLACK);
 		int ypos = this->height - this->line_height;
 		for (const IConsoleLine *print = IConsoleLine::Get(IConsoleWindow::scroll); print != NULL; print = print->previous) {
 			SetDParamStr(0, print->buffer);
diff --git a/src/fios_gui.cpp b/src/fios_gui.cpp
--- a/src/fios_gui.cpp
+++ b/src/fios_gui.cpp
@@ -351,14 +351,14 @@ public:
 			}
 
 			case SLWW_DRIVES_DIRECTORIES_LIST: {
-				GfxFillRect(r.left + 1, r.top + 1, r.right, r.bottom, GREY_SCALE(1));
+				GfxFillRect(r.left + 1, r.top + 1, r.right, r.bottom, PC_BLACK);
 
 				uint y = r.top + WD_FRAMERECT_TOP;
 				for (uint pos = this->vscroll->GetPosition(); pos < _fios_items.Length(); pos++) {
 					const FiosItem *item = _fios_items.Get(pos);
 
 					if (item == this->selected) {
-						GfxFillRect(r.left + 1, y, r.right, y + this->resize.step_height, 156);
+						GfxFillRect(r.left + 1, y, r.right, y + this->resize.step_height, PC_DARK_BLUE);
 					}
 					DrawString(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, y, item->title, _fios_colours[item->type]);
 					y += this->resize.step_height;
@@ -369,7 +369,7 @@ public:
 
 			case SLWW_DETAILS: {
 				GfxFillRect(r.left + WD_FRAMERECT_LEFT, r.top + WD_FRAMERECT_TOP,
-						r.right - WD_FRAMERECT_RIGHT, r.top + FONT_HEIGHT_NORMAL * 2 + WD_FRAMERECT_TOP + WD_FRAMERECT_BOTTOM, GREY_SCALE(10));
+						r.right - WD_FRAMERECT_RIGHT, r.top + FONT_HEIGHT_NORMAL * 2 + WD_FRAMERECT_TOP + WD_FRAMERECT_BOTTOM, PC_GREY);
 				DrawString(r.left, r.right, r.top + FONT_HEIGHT_NORMAL / 2 + WD_FRAMERECT_TOP, STR_SAVELOAD_DETAIL_CAPTION, TC_FROMSTRING, SA_HOR_CENTER);
 
 				if (this->selected == NULL) break;
diff --git a/src/gfx.cpp b/src/gfx.cpp
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -264,7 +264,7 @@ void DrawBox(int x, int y, int dx1, int 
 	 *            ....V.
 	 */
 
-	static const byte colour = GREY_SCALE(15);
+	static const byte colour = PC_WHITE;
 
 	GfxDrawLineUnscaled(x, y, x + dx1, y + dy1, colour);
 	GfxDrawLineUnscaled(x, y, x + dx2, y + dy2, colour);
diff --git a/src/gfx_func.h b/src/gfx_func.h
--- a/src/gfx_func.h
+++ b/src/gfx_func.h
@@ -189,4 +189,20 @@ extern bool _palette_remap_grf[];
  */
 #define GREY_SCALE(level) (level)
 
+static const uint8 PC_BLACK              = GREY_SCALE(1);  ///< Black palette colour.
+static const uint8 PC_GREY               = GREY_SCALE(10); ///< Grey palette colour.
+static const uint8 PC_WHITE              = GREY_SCALE(15); ///< White palette colour.
+
+static const uint8 PC_VERY_DARK_RED      = 0xB2;           ///< Almost-black red palette colour.
+static const uint8 PC_DARK_RED           = 0xB4;           ///< Dark red palette colour.
+static const uint8 PC_RED                = 0xB8;           ///< Red palette colour.
+
+static const uint8 PC_YELLOW             = 0xBF;           ///< Yellow palette colour.
+static const uint8 PC_LIGHT_YELLOW       = 0x44;           ///< Light yellow palette colour.
+static const uint8 PC_VERY_LIGHT_YELLOW  = 0x45;           ///< Almost-white yellow palette colour.
+
+static const uint8 PC_GREEN              = 0xD0;           ///< Green palette colour.
+
+static const uint8 PC_DARK_BLUE          = 0x9D;           ///< Dark blue palette colour.
+
 #endif /* GFX_FUNC_H */
diff --git a/src/graph_gui.cpp b/src/graph_gui.cpp
--- a/src/graph_gui.cpp
+++ b/src/graph_gui.cpp
@@ -177,7 +177,7 @@ enum CompanyValueWidgets {
 struct BaseGraphWindow : Window {
 protected:
 	static const int GRAPH_MAX_DATASETS     =  32;
-	static const int GRAPH_AXIS_LINE_COLOUR = GREY_SCALE(1);
+	static const int GRAPH_AXIS_LINE_COLOUR = PC_BLACK;
 	static const int GRAPH_NUM_MONTHS       =  24; ///< Number of months displayed in the graph.
 
 	static const int MIN_GRAPH_NUM_LINES_Y  =   9; ///< Minimal number of horizontal lines to draw.
@@ -977,7 +977,7 @@ struct PaymentRatesGraphWindow : BaseGra
 
 		int rect_x = clk_dif + (rtl ? r.right - 12 : r.left + WD_FRAMERECT_LEFT);
 
-		GfxFillRect(rect_x, y + clk_dif, rect_x + 8, y + 5 + clk_dif, GREY_SCALE(0));
+		GfxFillRect(rect_x, y + clk_dif, rect_x + 8, y + 5 + clk_dif, PC_BLACK);
 		GfxFillRect(rect_x + 1, y + 1 + clk_dif, rect_x + 7, y + 4 + clk_dif, cs->legend_colour);
 		SetDParam(0, cs->name);
 		DrawString(rtl ? r.left : x + 14 + clk_dif, (rtl ? r.right - 14 + clk_dif : r.right), y + clk_dif, STR_GRAPH_CARGO_PAYMENT_CARGO);
@@ -1425,7 +1425,7 @@ struct PerformanceRatingDetailWindow : W
 
 		ScoreID score_type = (ScoreID)(widget - PRW_SCORE_FIRST);
 
-			/* The colours used to show how the progress is going */
+		/* The colours used to show how the progress is going */
 		int colour_done = _colour_gradient[COLOUR_GREEN][4];
 		int colour_notdone = _colour_gradient[COLOUR_RED][4];
 
diff --git a/src/industry_gui.cpp b/src/industry_gui.cpp
--- a/src/industry_gui.cpp
+++ b/src/industry_gui.cpp
@@ -396,7 +396,7 @@ public:
 
 					/* Draw the name of the industry in white is selected, otherwise, in orange */
 					DrawString(x + MATRIX_TEXT_OFFSET, r.right - WD_MATRIX_RIGHT, y, indsp->name, selected ? TC_WHITE : TC_ORANGE);
-					GfxFillRect(x,     y + 1,  x + 10, y + 7, selected ? GREY_SCALE(15) : GREY_SCALE(0));
+					GfxFillRect(x,     y + 1,  x + 10, y + 7, selected ? PC_WHITE : PC_BLACK);
 					GfxFillRect(x + 1, y + 2,  x +  9, y + 6, indsp->map_colour);
 				}
 				break;
@@ -1677,7 +1677,7 @@ struct CargoesField {
 						blob_left  = xpos + BLOB_DISTANCE;
 						blob_right = blob_left + BLOB_WIDTH;
 					}
-					GfxFillRect(blob_left,     ypos2 - BLOB_DISTANCE - BLOB_HEIGHT,     blob_right,     ypos2 - BLOB_DISTANCE,     GREY_SCALE(0)); // Border
+					GfxFillRect(blob_left,     ypos2 - BLOB_DISTANCE - BLOB_HEIGHT,     blob_right,     ypos2 - BLOB_DISTANCE,     PC_BLACK); // Border
 					GfxFillRect(blob_left + 1, ypos2 - BLOB_DISTANCE - BLOB_HEIGHT + 1, blob_right - 1, ypos2 - BLOB_DISTANCE - 1, indsp->map_colour);
 				} else {
 					DrawString(xpos, xpos2, ypos, STR_INDUSTRY_CARGOES_HOUSES, TC_FROMSTRING, SA_HOR_CENTER);
@@ -1899,8 +1899,8 @@ const int CargoesField::BLOB_HEIGHT   = 
 /** Width of a #CFT_CARGO field. */
 const int CargoesField::CARGO_FIELD_WIDTH = HOR_CARGO_BORDER_SPACE * 2 + HOR_CARGO_WIDTH * MAX_CARGOES + HOR_CARGO_SPACE * (MAX_CARGOES - 1);
 
-const int CargoesField::INDUSTRY_LINE_COLOUR = 191; ///< Line colour of the industry type box.
-const int CargoesField::CARGO_LINE_COLOUR    = 191; ///< Line colour around the cargo.
+const int CargoesField::INDUSTRY_LINE_COLOUR = PC_YELLOW; ///< Line colour of the industry type box.
+const int CargoesField::CARGO_LINE_COLOUR    = PC_YELLOW; ///< Line colour around the cargo.
 
 /** A single row of #CargoesField. */
 struct CargoesRow {
diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -930,8 +930,8 @@ struct TooltipsWindow : public Window
 	virtual void DrawWidget(const Rect &r, int widget) const
 	{
 		/* There is only one widget. */
-		GfxFillRect(r.left, r.top, r.right, r.bottom, GREY_SCALE(0));
-		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, 0x44);
+		GfxFillRect(r.left, r.top, r.right, r.bottom, PC_BLACK);
+		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_LIGHT_YELLOW);
 
 		for (uint arg = 0; arg < this->paramcount; arg++) {
 			SetDParam(arg, this->params[arg]);
@@ -1303,7 +1303,7 @@ void QueryString::DrawEditBox(Window *w,
 	int top    = wi->pos_y;
 	int bottom = wi->pos_y + wi->current_y - 1;
 
-	GfxFillRect(left + 1, top + 1, right - 1, bottom - 1, GREY_SCALE(1));
+	GfxFillRect(left + 1, top + 1, right - 1, bottom - 1, PC_BLACK);
 
 	/* Limit the drawing of the string inside the widget boundaries */
 	DrawPixelInfo dpi;
diff --git a/src/music_gui.cpp b/src/music_gui.cpp
--- a/src/music_gui.cpp
+++ b/src/music_gui.cpp
@@ -370,7 +370,7 @@ struct MusicTrackSelectionWindow : publi
 	{
 		switch (widget) {
 			case MTSW_LIST_LEFT: {
-				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, GREY_SCALE(0));
+				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_BLACK);
 
 				int y = r.top + WD_FRAMERECT_TOP;
 				for (uint i = 0; i < NUM_SONGS_AVAILABLE; i++) {
@@ -387,7 +387,7 @@ struct MusicTrackSelectionWindow : publi
 			}
 
 			case MTSW_LIST_RIGHT: {
-				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, GREY_SCALE(0));
+				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_BLACK);
 
 				int y = r.top + WD_FRAMERECT_TOP;
 				for (const byte *p = _playlists[_settings_client.music.playlist]; *p != 0; p++) {
@@ -592,14 +592,14 @@ struct MusicWindow : public Window {
 	{
 		switch (widget) {
 			case MW_GAUGE:
-				GfxFillRect(r.left, r.top, r.right, r.bottom, GREY_SCALE(0));
+				GfxFillRect(r.left, r.top, r.right, r.bottom, PC_BLACK);
 
 				for (uint i = 0; i != 8; i++) {
-					int colour = 0xD0;
+					int colour = PC_GREEN;
 					if (i > 4) {
-						colour = 0xBF;
+						colour = PC_YELLOW;
 						if (i > 6) {
-							colour = 0xB8;
+							colour = PC_RED;
 						}
 					}
 					GfxFillRect(r.left, r.bottom - i * 2, r.right, r.bottom - i * 2, colour);
@@ -607,7 +607,7 @@ struct MusicWindow : public Window {
 				break;
 
 			case MW_TRACK_NR: {
-				GfxFillRect(r.left + 1, r.top + 1, r.right, r.bottom, GREY_SCALE(0));
+				GfxFillRect(r.left + 1, r.top + 1, r.right, r.bottom, PC_BLACK);
 				StringID str = STR_MUSIC_TRACK_NONE;
 				if (_song_is_active != 0 && _music_wnd_cursong != 0) {
 					SetDParam(0, GetTrackNumber(_music_wnd_cursong - 1));
@@ -619,7 +619,7 @@ struct MusicWindow : public Window {
 			}
 
 			case MW_TRACK_NAME: {
-				GfxFillRect(r.left, r.top + 1, r.right - 1, r.bottom, GREY_SCALE(0));
+				GfxFillRect(r.left, r.top + 1, r.right - 1, r.bottom, PC_BLACK);
 				StringID str = STR_MUSIC_TITLE_NONE;
 				if (_song_is_active != 0 && _music_wnd_cursong != 0) {
 					str = STR_MUSIC_TITLE_NAME;
diff --git a/src/network/network_content_gui.cpp b/src/network/network_content_gui.cpp
--- a/src/network/network_content_gui.cpp
+++ b/src/network/network_content_gui.cpp
@@ -455,7 +455,7 @@ public:
 		for (ConstContentIterator iter = this->content.Get(this->vscroll->GetPosition()); iter != this->content.End() && cnt < this->vscroll->GetCapacity(); iter++, cnt++) {
 			const ContentInfo *ci = *iter;
 
-			if (ci == this->selected) GfxFillRect(r.left + 1, y + 1, r.right - 1, y + this->resize.step_height - 1, GREY_SCALE(10));
+			if (ci == this->selected) GfxFillRect(r.left + 1, y + 1, r.right - 1, y + this->resize.step_height - 1, PC_GREY);
 
 			SpriteID sprite;
 			SpriteID pal = PAL_NONE;
@@ -491,7 +491,7 @@ public:
 		int DETAIL_TITLE_HEIGHT = 5 * FONT_HEIGHT_NORMAL;
 
 		/* Create the nice grayish rectangle at the details top */
-		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.top + DETAIL_TITLE_HEIGHT, 157);
+		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.top + DETAIL_TITLE_HEIGHT, PC_DARK_BLUE);
 		DrawString(r.left + WD_INSET_LEFT, r.right - WD_INSET_RIGHT, r.top + FONT_HEIGHT_NORMAL + WD_INSET_TOP, STR_CONTENT_DETAIL_TITLE, TC_FROMSTRING, SA_HOR_CENTER);
 
 		/* Draw the total download size */
diff --git a/src/network/network_gui.cpp b/src/network/network_gui.cpp
--- a/src/network/network_gui.cpp
+++ b/src/network/network_gui.cpp
@@ -382,7 +382,7 @@ protected:
 		const NWidgetBase *nwi_info = this->GetWidget<NWidgetBase>(NGWW_INFO);
 
 		/* show highlighted item with a different colour */
-		if (highlight) GfxFillRect(nwi_name->pos_x + 1, y - 2, nwi_info->pos_x + nwi_info->current_x - 2, y + FONT_HEIGHT_NORMAL - 1, GREY_SCALE(10));
+		if (highlight) GfxFillRect(nwi_name->pos_x + 1, y - 2, nwi_info->pos_x + nwi_info->current_x - 2, y + FONT_HEIGHT_NORMAL - 1, PC_GREY);
 
 		DrawString(nwi_name->pos_x + WD_FRAMERECT_LEFT, nwi_name->pos_x + nwi_name->current_x - WD_FRAMERECT_RIGHT, y, cur_item->info.server_name, TC_BLACK);
 
@@ -610,7 +610,7 @@ public:
 		const int detail_height = 6 + 8 + 6 + 3 * FONT_HEIGHT_NORMAL;
 
 		/* Draw the right menu */
-		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.top + detail_height - 1, 157);
+		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.top + detail_height - 1, PC_DARK_BLUE);
 		if (sel == NULL) {
 			DrawString(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, r.top + 6 + 4 + FONT_HEIGHT_NORMAL, STR_NETWORK_SERVER_LIST_GAME_INFO, TC_FROMSTRING, SA_HOR_CENTER);
 		} else if (!sel->online) {
@@ -1490,7 +1490,7 @@ struct NetworkLobbyWindow : public Windo
 			byte company = NetworkLobbyFindCompanyIndex(pos);
 			bool income = false;
 			if (this->company == company) {
-				GfxFillRect(r.left + 1, y - 2, r.right - 1, y + FONT_HEIGHT_NORMAL, GREY_SCALE(10)); // show highlighted item with a different colour
+				GfxFillRect(r.left + 1, y - 2, r.right - 1, y + FONT_HEIGHT_NORMAL, PC_GREY); // show highlighted item with a different colour
 			}
 
 			DrawString(text_left, text_right, y, this->company_info[company].company_name, TC_BLACK);
@@ -1510,7 +1510,7 @@ struct NetworkLobbyWindow : public Windo
 	{
 		const int detail_height = 12 + FONT_HEIGHT_NORMAL + 12;
 		/* Draw info about selected company when it is selected in the left window */
-		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.top + detail_height - 1, 157);
+		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.top + detail_height - 1, PC_DARK_BLUE);
 		DrawString(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, r.top + 12, STR_NETWORK_GAME_LOBBY_COMPANY_INFO, TC_FROMSTRING, SA_HOR_CENTER);
 
 		if (this->company == INVALID_COMPANY || StrEmpty(this->company_info[this->company].company_name)) return;
@@ -1826,7 +1826,7 @@ struct NetworkClientListPopupWindow : Wi
 		for (const ClientListAction *action = this->actions.Begin(); action != this->actions.End(); action++, y += FONT_HEIGHT_NORMAL) {
 			TextColour colour;
 			if (sel-- == 0) { // Selected item, highlight it
-				GfxFillRect(r.left + 1, y, r.right - 1, y + FONT_HEIGHT_NORMAL - 1, GREY_SCALE(0));
+				GfxFillRect(r.left + 1, y, r.right - 1, y + FONT_HEIGHT_NORMAL - 1, PC_BLACK);
 				colour = TC_WHITE;
 			} else {
 				colour = TC_BLACK;
@@ -1978,7 +1978,7 @@ struct NetworkClientListWindow : Window 
 		FOR_ALL_CLIENT_INFOS(ci) {
 			TextColour colour;
 			if (this->selected_item == i++) { // Selected item, highlight it
-				GfxFillRect(r.left + 1, y, r.right - 1, y + FONT_HEIGHT_NORMAL - 1, GREY_SCALE(0));
+				GfxFillRect(r.left + 1, y, r.right - 1, y + FONT_HEIGHT_NORMAL - 1, PC_BLACK);
 				colour = TC_WHITE;
 			} else {
 				colour = TC_BLACK;
diff --git a/src/newgrf_gui.cpp b/src/newgrf_gui.cpp
--- a/src/newgrf_gui.cpp
+++ b/src/newgrf_gui.cpp
@@ -695,7 +695,7 @@ struct NewGRFWindow : public QueryString
 	{
 		switch (widget) {
 			case SNGRFS_FILE_LIST: {
-				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, GREY_SCALE(1));
+				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_BLACK);
 
 				uint step_height = this->GetWidget<NWidgetBase>(SNGRFS_FILE_LIST)->resize_y;
 				uint y = r.top + WD_FRAMERECT_TOP;
@@ -715,7 +715,7 @@ struct NewGRFWindow : public QueryString
 						bool h = (this->active_sel == c);
 						PaletteID pal = this->GetPalette(c);
 
-						if (h) GfxFillRect(r.left + 1, y, r.right - 1, y + step_height - 1, 156);
+						if (h) GfxFillRect(r.left + 1, y, r.right - 1, y + step_height - 1, PC_DARK_BLUE);
 						DrawSprite(SPR_SQUARE, pal, square_left, y + sprite_offset_y);
 						if (c->error != NULL) DrawSprite(SPR_WARNING_SIGN, 0, warning_left, y + sprite_offset_y);
 						uint txtoffset = c->error == NULL ? 0 : 10;
@@ -727,7 +727,7 @@ struct NewGRFWindow : public QueryString
 			}
 
 			case SNGRFS_AVAIL_LIST: {
-				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, GREY_SCALE(1));
+				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_BLACK);
 
 				uint step_height = this->GetWidget<NWidgetBase>(SNGRFS_AVAIL_LIST)->resize_y;
 				int offset_y = (step_height - FONT_HEIGHT_NORMAL) / 2;
@@ -740,7 +740,7 @@ struct NewGRFWindow : public QueryString
 					bool h = (c == this->avail_sel);
 					const char *text = c->GetName();
 
-					if (h) GfxFillRect(r.left + 1, y, r.right - 1, y + step_height - 1, 156);
+					if (h) GfxFillRect(r.left + 1, y, r.right - 1, y + step_height - 1, PC_DARK_BLUE);
 					DrawString(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, y + offset_y, text, h ? TC_WHITE : TC_SILVER);
 					y += step_height;
 				}
@@ -749,7 +749,7 @@ struct NewGRFWindow : public QueryString
 
 			case SNGRFS_NEWGRF_INFO_TITLE:
 				/* Create the nice grayish rectangle at the details top. */
-				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, 157);
+				GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_DARK_BLUE);
 				DrawString(r.left, r.right, (r.top + r.bottom - FONT_HEIGHT_NORMAL) / 2, STR_NEWGRF_SETTINGS_INFO_TITLE, TC_FROMSTRING, SA_HOR_CENTER);
 				break;
 
diff --git a/src/news_gui.cpp b/src/news_gui.cpp
--- a/src/news_gui.cpp
+++ b/src/news_gui.cpp
@@ -335,12 +335,12 @@ struct NewsWindow : Window {
 
 	void DrawNewsBorder(const Rect &r) const
 	{
-		GfxFillRect(r.left,  r.top,    r.right, r.bottom, GREY_SCALE(15));
+		GfxFillRect(r.left,  r.top,    r.right, r.bottom, PC_WHITE);
 
-		GfxFillRect(r.left,  r.top,    r.left,  r.bottom, GREY_SCALE(1));
-		GfxFillRect(r.right, r.top,    r.right, r.bottom, GREY_SCALE(1));
-		GfxFillRect(r.left,  r.top,    r.right, r.top,    GREY_SCALE(1));
-		GfxFillRect(r.left,  r.bottom, r.right, r.bottom, GREY_SCALE(1));
+		GfxFillRect(r.left,  r.top,    r.left,  r.bottom, PC_BLACK);
+		GfxFillRect(r.right, r.top,    r.right, r.bottom, PC_BLACK);
+		GfxFillRect(r.left,  r.top,    r.right, r.top,    PC_BLACK);
+		GfxFillRect(r.left,  r.bottom, r.right, r.bottom, PC_BLACK);
 	}
 
 	virtual Point OnInitialPosition(const WindowDesc *desc, int16 sm_width, int16 sm_height, int window_number)
@@ -425,7 +425,7 @@ struct NewsWindow : Window {
 				break;
 
 			case NTW_VEH_BKGND:
-				GfxFillRect(r.left, r.top, r.right, r.bottom, GREY_SCALE(10));
+				GfxFillRect(r.left, r.top, r.right, r.bottom, PC_GREY);
 				break;
 
 			case NTW_VEH_NAME:
diff --git a/src/object_gui.cpp b/src/object_gui.cpp
--- a/src/object_gui.cpp
+++ b/src/object_gui.cpp
@@ -206,7 +206,7 @@ public:
 				if (spec == NULL) break;
 
 				if (!spec->IsAvailable()) {
-					GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, GREY_SCALE(0), FILLRECT_CHECKER);
+					GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_BLACK, FILLRECT_CHECKER);
 				}
 				DrawPixelInfo tmp_dpi;
 				/* Set up a clipping area for the preview. */
diff --git a/src/rail_gui.cpp b/src/rail_gui.cpp
--- a/src/rail_gui.cpp
+++ b/src/rail_gui.cpp
@@ -1163,7 +1163,7 @@ public:
 				const StationSpec *statspec = StationClass::Get(_railstation.station_class, type);
 				if (statspec != NULL && HasBit(statspec->callback_mask, CBM_STATION_AVAIL) &&
 						GB(GetStationCallback(CBID_STATION_AVAILABILITY, 0, 0, statspec, NULL, INVALID_TILE), 0, 8) == 0) {
-					GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, GREY_SCALE(0), FILLRECT_CHECKER);
+					GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_BLACK, FILLRECT_CHECKER);
 				}
 
 				/* Set up a clipping area for the station preview. */
@@ -1815,7 +1815,7 @@ struct BuildRailWaypointWindow : PickerW
 				if (statspec != NULL &&
 						HasBit(statspec->callback_mask, CBM_STATION_AVAIL) &&
 						GB(GetStationCallback(CBID_STATION_AVAILABILITY, 0, 0, statspec, NULL, INVALID_TILE), 0, 8) == 0) {
-					GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, 0, FILLRECT_CHECKER);
+					GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, PC_BLACK, FILLRECT_CHECKER);
 				}
 			}
 		}
diff --git a/src/smallmap_gui.cpp b/src/smallmap_gui.cpp
--- a/src/smallmap_gui.cpp
+++ b/src/smallmap_gui.cpp
@@ -893,8 +893,8 @@ class SmallMapWindow : public Window {
 	 */
 	static inline void DrawVertMapIndicator(int x, int y, int y2)
 	{
-		GfxFillRect(x, y,      x, y + 3, 69);
-		GfxFillRect(x, y2 - 3, x, y2,    69);
+		GfxFillRect(x, y,      x, y + 3, PC_VERY_LIGHT_YELLOW);
+		GfxFillRect(x, y2 - 3, x, y2,    PC_VERY_LIGHT_YELLOW);
 	}
 
 	/**
@@ -905,8 +905,8 @@ class SmallMapWindow : public Window {
 	 */
 	static inline void DrawHorizMapIndicator(int x, int x2, int y)
 	{
-		GfxFillRect(x,      y, x + 3, y, 69);
-		GfxFillRect(x2 - 3, y, x2,    y, 69);
+		GfxFillRect(x,      y, x + 3, y, PC_VERY_LIGHT_YELLOW);
+		GfxFillRect(x2 - 3, y, x2,    y, PC_VERY_LIGHT_YELLOW);
 	}
 
 	/**
@@ -952,7 +952,7 @@ class SmallMapWindow : public Window {
 		_cur_dpi = dpi;
 
 		/* Clear it */
-		GfxFillRect(dpi->left, dpi->top, dpi->left + dpi->width - 1, dpi->top + dpi->height - 1, GREY_SCALE(0));
+		GfxFillRect(dpi->left, dpi->top, dpi->left + dpi->width - 1, dpi->top + dpi->height - 1, PC_BLACK);
 
 		/* Which tile is displayed at (dpi->left, dpi->top)? */
 		int dx;
@@ -1204,7 +1204,7 @@ public:
 							DrawString(x + text_left, x + text_right, y, STR_SMALLMAP_INDUSTRY, TC_GREY);
 						} else {
 							DrawString(x + text_left, x + text_right, y, STR_SMALLMAP_INDUSTRY, TC_BLACK);
-							GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, GREY_SCALE(0)); // Outer border of the legend colour
+							GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, PC_BLACK); // Outer border of the legend colour
 						}
 					} else if (this->map_type == SMT_OWNER && tbl->company != INVALID_COMPANY) {
 						SetDParam(0, tbl->company);
@@ -1214,13 +1214,13 @@ public:
 							DrawString(x + text_left, x + text_right, y, STR_SMALLMAP_COMPANY, TC_GREY);
 						} else {
 							DrawString(x + text_left, x + text_right, y, STR_SMALLMAP_COMPANY, TC_BLACK);
-							GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, GREY_SCALE(0)); // Outer border of the legend colour
+							GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, PC_BLACK); // Outer border of the legend colour
 						}
 					} else {
 						if (this->map_type == SMT_CONTOUR) SetDParam(0, tbl->height * TILE_HEIGHT_STEP);
 
 						/* Anything that is not an industry or a company is using normal process */
-						GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, GREY_SCALE(0));
+						GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, PC_BLACK);
 						DrawString(x + text_left, x + text_right, y, tbl->legend);
 					}
 					GfxFillRect(x + blob_left + 1, y + 2, x + blob_right - 1, y + row_height - 2, tbl->colour); // Legend colour
diff --git a/src/station_gui.cpp b/src/station_gui.cpp
--- a/src/station_gui.cpp
+++ b/src/station_gui.cpp
@@ -168,9 +168,9 @@ static void StationsWndShowStationRating
 
 	/* Draw green/red ratings bar (fits into 14 pixels) */
 	y += height + 2;
-	GfxFillRect(left + 1, y, left + 14, y, 0xB8);
+	GfxFillRect(left + 1, y, left + 14, y, PC_RED);
 	rating = minu(rating, rating_full) / 16;
-	if (rating != 0) GfxFillRect(left + 1, y, left + rating, y, 0xD0);
+	if (rating != 0) GfxFillRect(left + 1, y, left + rating, y, PC_GREEN);
 }
 
 typedef GUIList<const Station*> GUIStationList;
diff --git a/src/toolbar_gui.cpp b/src/toolbar_gui.cpp
--- a/src/toolbar_gui.cpp
+++ b/src/toolbar_gui.cpp
@@ -1133,8 +1133,8 @@ public:
 	/* virtual */ void Draw(const Window *w)
 	{
 		/* Draw brown-red toolbar bg. */
-		GfxFillRect(this->pos_x, this->pos_y, this->pos_x + this->current_x - 1, this->pos_y + this->current_y - 1, 0xB2);
-		GfxFillRect(this->pos_x, this->pos_y, this->pos_x + this->current_x - 1, this->pos_y + this->current_y - 1, 0xB4, FILLRECT_CHECKER);
+		GfxFillRect(this->pos_x, this->pos_y, this->pos_x + this->current_x - 1, this->pos_y + this->current_y - 1, PC_VERY_DARK_RED);
+		GfxFillRect(this->pos_x, this->pos_y, this->pos_x + this->current_x - 1, this->pos_y + this->current_y - 1, PC_DARK_RED, FILLRECT_CHECKER);
 
 		bool rtl = _current_text_dir == TD_RTL;
 		for (NWidgetBase *child_wid = rtl ? this->tail : this->head; child_wid != NULL; child_wid = rtl ? child_wid->prev : child_wid->next) {
diff --git a/src/widgets/dropdown.cpp b/src/widgets/dropdown.cpp
--- a/src/widgets/dropdown.cpp
+++ b/src/widgets/dropdown.cpp
@@ -248,7 +248,7 @@ struct DropdownWindow : Window {
 
 			if (y + item_height < r.bottom) {
 				bool selected = (this->selected_index == item->result);
-				if (selected) GfxFillRect(r.left + 2, y, r.right - 1, y + item_height - 1, GREY_SCALE(0));
+				if (selected) GfxFillRect(r.left + 2, y, r.right - 1, y + item_height - 1, PC_BLACK);
 
 				item->Draw(r.left, r.right, y, r.bottom, selected, colour);