it depends on how Truespace handles mapping, I s'pose. If there's a way to differentiate the colored areas you want to use, you can name them (or color them), then using Ctrl+Right Mouse click, and you can select the named areas, and apply mats from Bryce into them. If you can do that, that's how I usually wind up doing it.
There's another thing called UVMapper Classic, which you can get for free off the Web. While more involved, you can use more detailed textures (jpgs off the web, for example) to play with the big boys. I don't have the URL for the site, but there's a UVMapper forum, drop by and they'll set you right..;)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)