I think I'll just use the lighter prints for the background on the remaining three blocks which will balance and minimize the amount of white. The nice thing about scrappy is that you almost can't go wrong. If you have color values that are similar, but prints are different they will still look good. I call these the sherbert colors because that is what they remind me of. You are right of course, I probably wouldn't add a lot of black to this selection, but you probably wouldn't go wrong with teal, turquise, tan, cream, light blue,etc..