diff --git a/src/linkgraph/linkgraph_gui.cpp b/src/linkgraph/linkgraph_gui.cpp
--- a/src/linkgraph/linkgraph_gui.cpp
+++ b/src/linkgraph/linkgraph_gui.cpp
@@ -375,7 +375,7 @@ void LinkGraphOverlay::SetCompanyMask(ui
 /** Make a number of rows with buttons for each company for the linkgraph legend window. */
 NWidgetBase *MakeCompanyButtonRowsLinkGraphGUI(int *biggest_index)
 {
-	return MakeCompanyButtonRows(biggest_index, WID_LGL_COMPANY_FIRST, WID_LGL_COMPANY_LAST, 3, STR_NULL);
+	return MakeCompanyButtonRows(biggest_index, WID_LGL_COMPANY_FIRST, WID_LGL_COMPANY_LAST, COLOUR_GREY, 3, STR_NULL);
 }
 
 NWidgetBase *MakeSaturationLegendLinkGraphGUI(int *biggest_index)