My friend Lisa, who's in my quilt guild, just sent a link to a Color Hue Test. I looked at it and thought it would be easy, but it was tricky. As similar colors are grouped together, it gets harder and harder to distinguish among the subtle shades. I didn't have the time/patience to do more than the first section this morning, but when I clicked to score the test, it showed me graphically how well each section was put in order. Give it a try, and have fun!