I have been told I just have an eye for color. But, if you don't you can use the dots in the selvage of your fabric. Pick a nice print that you may use on a border and there should be enough color dots for you to choose which color you want put into your quilt. I am not too fond of solids as they get boring if you have too much. Choose different scales of prints. Large, medium small and one that reads as a solid. Line up your bolts and stand back. They look different in smaller pieces and from a distance than if you hold each separate. Then again you can always choose fabrics that are in a particular line made to go together.