I often find a novelty fabric and I use the dye dots along the selvage to pick coordinating colors. The one thing that really helped my color choices ( and I learn something on EVERY quilt about color!), is using a design wall. If I think I need a yellow, I tack up 3 or 4 choices. As I pass by, working on something else, I take off the ones that really DON"T work...until finally I have my choice.