[styles] Improved general and pedestrian area visibility

Signed-off-by: Yannik Bloscheck <git@yannikbloscheck.com>

data/styles/default/dark/colors.mapcss

@@ -98,10 +98,8 @@
 
 @general_area: #000000;
 @pedestrian_area: #262222;
-@pedestrian_area_light: #262222;
 @railway_platform: #262222;
 @university: #261F13;
-@retail: #130C11;
 @hospital: #261916;
 @industrial: #191419;
 @construction_area: #191419;