Thank you, thank you!
I have to say I don't like the colors used in the book. Most of them are dark so that's why I changed the colors of most blocks I did. One block I made I don't like and I might do that one again.
Red/blue/green/brown and off white seems a good choice to me. Why don't you put them together and see how it looks. Post a picture of what you have, that might help as well.