Local maps are grayscale as you can see here: http://www.uesp.net/maps/srmap/srmap.shtml (In CK: World > Create Local Maps)
Although a similar function on Oblivion's Construction Set rendered the world in color: http://www.uesp.net/maps/obmap/obmap.shtml
I wonder why Bethesda chose to render Skyrim's local maps in grayscale. It would be endlessly more useful to have a color render and then turn it grayscale later if needed.

I would assume this grayscale rendering simply a switch somewhere in the CK code that discards all color information. Is there any way to render a local map in full color? I would assume you need to somehow modify the .EXE file to prevent it from discarding the texture color information or something like that. Anyone have any ideas?