I envy many quilt artists for their ability to use color, shape, and concept. They are able to use fabric to convey depth to “paint” a near-photo-like images (Lura Schwarz Smith's Seams a Lot Like Degas, Margot Lovinger's Untitled with Rose). Or use the shape of the quilt to enhance the motion and rhythm of the subject (The wavy borders of Moonglow Anemone by Carla Stehr). Or such effective use of color that the quilt simply vibrates with energy (Paula Nadelstem's kaleidoscope quilts, Plum Tango II by Janet Kurjan and Bonny Brewer’s Counterpoint). Or use color and stitching to convey movement (again Paula's kaleidoscope quilts, Melisse Laing's Whirlpool). Or how simply changing the colors in a quilt pattern changes the mood as in Jan Krentz's Lone Star quilts.
There are many sources to help you learn how to understand color. The picture is of a Tumbling Blocks quilt I did a few years ago. I am better than I was, but have so much farther to go. Here are a few sources. Jinny Beyer's Color Confidence For Quilters. Color for Quilters, Secrets for Color Success in Quiltmaking by Laui Linch-Zadel and Belina Sturgis. Color Play: Easy Steps to Imaginative Color in Quilts byJoen Wolfrom. A nice "Workshop on Saturation" with a practice block at quiltwoman.com.