I love color, well most all color, except orange/browns. I think there are two topics here: color and value. I've read many books on color, worked in watercolor. I've developed "my color/value voice" and people can pick out my quilts by the color/value. I've picked out colors by the registration marks, color wheels, focus fabrics.
One method I've used is to cut out pictures I like from magazines and keep a binder of this info. I'll pick a "moody" picture, one that strikes a mood, it might be happy or sad, doesn't matter, just has a mood. Then pick out the colors from that picture. I make sure there is a variety of values too. Then I hunt fabric from these colors and attached 1/2 x 2 inch pieces around the edge of the picture. To me 100 different fabrics are more interesting than 5, so I include all fabrics that are remotely close. Here's an example:[ATTACH=CONFIG]412074[/ATTACH]