I figured out a way to increase the number of colors available in the Picture Channel of the Wii. Just put a color palette in the picture, but rather then just telling everyone about it, I figured I could make it for you so all you have to do is download the picture and send it to your Wii. (either via your SDcard or e-mail).
I started a new thread for it, because I figured we can all share the drawings we make with it.
here's the link to the thread.