It is Easter time. So I thought it was time to share one Mapserver Easter Egg that I have found. In some old mapfile examples it seems like there is a method to get transparent color by giving a -1 for the red value. This is not documented, so I started to experiment.
So if You would like to get a nice yellow color for the chickens use: -5 -20 0 To get a nice Santa red color use: -2 200 200 For a nice green color for green plants: 128 -2 128 Finally -255 -255 -255 gives You black color.