I have found that even though red is my favorite color, and pink is second, those are my smallest piles in the stash closet. The biggest is blue, then green. I actually have the blues divided into 3 piles (dark , light and turquoise-ish) And the greens are in light and dark piles.
What I seem to buy every time is nature themed, also. Fall is my favorite time of year because of the colors on the trees I grew up seeing (in PA and VA.) Its just so amazing to see that incredible burst of color as the summer disappears and the cool air of autumn settles in. The earth relaxing and getting ready to rest with one big show for the finale.
If there is a special project, I have non-nature prints and colors, like all the purples I bought because my daughter wanted a purple quilt, and of course as soon as I had stock piled enough, she was in her "black period," so I had to collect black and white fabrics for the Three Bean Salad quilt I made for her. It did turn out gorgeous. She was 16 when I made it for her and now that she's 18, it is still in a plastic storage bag cause she doesn't want to mess it up. LOL
I guess it may grace her bed when she's married someday.