Thanks, everyone.
Elise1- all my color blocks are from scraps, some of which were given to me by others. I learned a lot about color from several sources. One of the best for understanding color in quilt fabrics was an iquilt course that I took. It was taught by Katie Pasquini Masopust and It is still available if you go to the AQS website and then look for their Iquilt classes. For the color block quilts I first decide on a color scheme and then when I am choosing the specific fabrics within that scheme I focus on value (how light or dark a fabric is in relation to the other fabrics in the quilt).
Rob