Fix SetColourRemap when using TC_FORCED | TC_BLACK

src/gfx.cpp

@@ -476,7 +476,7 @@ static void SetColourRemap(TextColour colour)
 
 	/* Black strings have no shading ever; the shading is black, so it
 	 * would be invisible at best, but it actually makes it illegible. */
-	bool no_shade   = (colour & TC_NO_SHADE) != 0 || colour == TC_BLACK;
+	bool no_shade   = (colour & TC_NO_SHADE) != 0 || (colour & ~TC_FORCED) == TC_BLACK;
 	bool raw_colour = (colour & TC_IS_PALETTE_COLOUR) != 0;
 	colour &= ~(TC_NO_SHADE | TC_IS_PALETTE_COLOUR | TC_FORCED);