I think the City Of Doors Initiative is still looking for volounteers to do character and NPC portraits for their Sigil reconstruction for Neverwinter Nights (here).
Hmmm, this is going to be hard without putting another colour image here for comparison, but I don't want to do that, since it might insult the artist who did it. What I mean is that a lot of the other colour images don't focus very much on detail. They're just a rough outline, with some colour to fill in. They're almost cartoon-ish in nature. With Romus's images, you can see a vast amount of detail, and the shading he (she? sorry if you're a she ) uses is quite incredible.