homebrew? This demonstration of what is possible with the homebrew drawing program Colors! will boot you off the fence and send you shopping for an R4. All you need to create gorgeous watercolor-looking portraits like this one is homebrew capability, the Colors! program, and to be Joe Quinones. Which, unfortunately, you aren't. Unless you are, in which case you've already seen these.
In addition to this portrait, he painted a lovely Princess Leia portrait that we think would be quite an achievement even if it hadn't been made with a DS. It proves that Star Wars fan works don't necessarily have to be embarrassing for everyone involved or watching.