I personally think you have to have some type of color scheme for a sampler quilt to look decent. I was in a guild once and we had a sampler quilt lesson each month. I decided to go with about 4 colors and used the same background. The 4 colors did vary and had different prints each, maybe the gold had 5 or 6 prints but they all went together. Another woman just made them out of whatever and when she showed her quilt, it wasn't pretty at all even though she did a good job making the blocks. My quilt turned out great, the quilt top just looked connected.