I used white and light ivory for the background so that the yellow would pop.
A border might be a good idea to square up the block.
These are stars made from material I got from my sister's mother-in-law. I think they will make a nice Quilt of valor. There are about six different plaids. They look very much like a Civil War Quilt I saw on the web. The colors are very subdued so it is great to work on the color balls in between!