Do a search for MTS themes on Google and you'll find a LOT of themes. That shows that themes are already supported. You can easily change the color palette, though you are still limited to 16 colors. The toolbar can also be changed easily. If you want even more control, there are DLLs that can allow you to create/use even more interesting themes.
There are many requests for more colors instead of limiting it to 16 colors at a time and I'm sure that's on Khaled's to-do list already.