I like these two as well. As far as complementary colors go, orange and blue is my favorite combination (which is why I painted the doorframes in my place orange while my carpet is blue for example).
And yeah, it was practical to be able to copy the motif to play with it, though it takes me longer to color something on the computer than on paper. So for regular art CG's main advantage for me is really the undo-function, and the opportunities to try different things, not that I find it easier or faster than using acrylics or water color.