If you could assign a couple of color attributes you would be pretty much on the way to a Cel Shader or Color Inker (something like what Illustrate! does in MAX). Like maybe at least being able to assign a Grey Scale value also- so with Black, Grey and White you could assign three color values to them. This could be done in "post" also (like Photoshop) but if possible in your application... it would be another leap forward!