make the main menu logo pulse

src/itdelatrisu/opsu/ui/Colors.java

@@ -45,7 +45,8 @@ public class Colors {
 		BLUE_SCOREBOARD = new Color(133, 208, 212),
 		BLACK_BG_NORMAL = new Color(0, 0, 0, 0.25f),
 		BLACK_BG_HOVER  = new Color(0, 0, 0, 0.5f),
-		BLACK_BG_FOCUS  = new Color(0, 0, 0, 0.75f);
+		BLACK_BG_FOCUS  = new Color(0, 0, 0, 0.75f),
+		GHOST_LOGO      = new Color(1.0f, 1.0f, 1.0f, 0.25f);
 
 	// This class should not be instantiated.
 	private Colors() {}