I would probably not go with a lot of different colors, since the Cover itself is already colorful.
The yellow in particular seems to be a little much. Maybe stay with it being white, or go with the same red you use below.
Other than that, I do find that it looks okay the way it is. It's a bit far up, though.
I take more issue with the way the author is slapped on, because it doesn't fit the rest.