If you read the descriptions it tells you the type of Pictures they use for the backgrounds.
For example I think the orange one is retro, so the BG pics are more retro-y.
The pink one is more girly backgrounds. But if you're going to be covering them up, it won't really matter, I guess.
If you can, go to Amazon and click on each color book. There are images of the inside pages and it will give you an idea. Or you can just wait until you go to Ms.