Merge branch 'master' into jgrpp

# Conflicts:
#	CMakeLists.txt
#	bin/ai/CMakeLists.txt
#	bin/game/CMakeLists.txt
#	src/ai/ai_info.cpp
#	src/company_base.h
#	src/economy.cpp
#	src/game/game_info.cpp
#	src/gfx_type.h
#	src/linkgraph/linkgraph_gui.cpp
#	src/palette.cpp
#	src/palette_func.h
#	src/saveload/saveload.h
#	src/saveload/vehicle_sl.cpp
#	src/ship_cmd.cpp
#	src/train_cmd.cpp
#	src/vehicle_base.h
#	src/window.cpp
#	src/window_func.h

src/viewport.cpp

@@ -2464,7 +2464,7 @@ static void ViewportDrawStrings(ViewportDrawerDynamic *vdd, ZoomLevel zoom, cons
 				/* Don't draw the rectangle.
 				 * Real colours need the TC_IS_PALETTE_COLOUR flag.
 				 * Otherwise colours from _string_colourmap are assumed. */
-				colour = (TextColour)_colour_gradient[ss.colour][6] | TC_IS_PALETTE_COLOUR;
+				colour = (TextColour)GetColourGradient(ss.colour, SHADE_LIGHTER) | TC_IS_PALETTE_COLOUR;
 			} else {
 				/* Draw the rectangle if 'transparent station signs' is off,
 				 * or if we are drawing a general text sign (STR_WHITE_SIGN). */