diff --git a/src/main_gui.cpp b/src/main_gui.cpp
--- a/src/main_gui.cpp
+++ b/src/main_gui.cpp
@@ -540,11 +540,12 @@ void ShowSelectGameWindow();
  */
 void SetupColoursAndInitialWindow()
 {
-	for (uint i = 0; i != 16; i++) {
+	for (Colours i = COLOUR_BEGIN; i != COLOUR_END; i++) {
 		const byte *b = GetNonSprite(GENERAL_SPRITE_COLOUR(i), SpriteType::Recolour);
-
-		assert(b);
-		memcpy(_colour_gradient[i], b + 0xC6, sizeof(_colour_gradient[i]));
+		assert(b != nullptr);
+		for (uint j = 0; j < 8; j++) {
+			SetColourGradient(i, j, b[0xC6 + j]);
+		}
 	}
 
 	new MainWindow(&_main_window_desc);