It is really not that hard to pick your colors. There is a simple Bargello with 2.5" strips cut and the use of 12 fabric. The pattern is called Serenity Bargello and can be found on Northcott website. I made this from scraps that RK donated to my church's sewing group using this pattern.
NOTE; If you want to make the fabric choice simple, just pick 12 colors of the rainbow. I did that with this table runner.