The double wedding ring in Rainbow colors is great, but that pattern scares me. If it is too complicated for you, how about a blooming 9 patch?
The pattern comes from a book called traditions with a twist. I made one in rainbow colors, and it was striking. I don't have a picture of mine but here is a link to a blog with a picture.
http://bigforkbaycottonco.blogspot.c...ine-patch.html