water colors are crazy hard! though I think if you use a colored theme it should be pretty easy if you use some water to dilute some of the color for the lighter areas or layer areas for shadows I think...I don't have a lot of experience w/ water colors, but I remember what I learned when I had to do an assignment for an art class lol I kinda try to think of 'em like markers. Same concept of mixing colors and what not, just...a lot more effort for making colors lol