How to make custom maps?

[bone_daddy]

Quick question. Well, maybe not so quick.

Apart from a white dot to designate a province and red lines for borders, are there any other special colors required for making maps. BTW, I've also noticed that some maps use other colors for borders, and at least one (Faerun) doesn't seem to use anything to indicate borders.

I've noticed that the random maps produced using dommap have certain colors assigned to certain terrain types. Are these colors just what the creator of dommap decided to assign the terrain type?

Or is only the white province dot what matters, and is everything else just handled by the *.map file?