I like to use solids to set off my pattern. I had a lady tell me that using solids were too old fashioned.
I tried my darnnest to try to put a poinsettia block together recently using some prints with the main color. Did not like it at all. I went back to the red solid and muslin.
I think a lot depends upon your eye for color matching also. I am not good at this at all. But can put fabrics together using the solids.
Bottom line use fabrics you like.