Yikes, that is a tough question. I love all the colors so that isn't any help.
For me, my favorites and least favorites are more about the type of fabric. I love batiks, bright and jewel tone prints, florals, border prints, and the neutrals.
I'm not a big fan of 30's, civil war repo's, thimbleberries, and homespuns. But my likes are just mine. There are many, many quilters that love these types of fabric.
It's the same thing with patterns. I gravitate to the more modern contemporary patterns, but there are quilters devoted to the traditional ones.
Perhaps you could go to the other LQS's in your area to see what they are stocking, or maybe contact some of the local long arm quilters and ask them about what types/colors of quilts they are seeing.
I wish you every success in your new business. :wink: