If you have a printer you can lay them out with a sliver showing of each color and copy them in B & W. Also try arranging them in dark to light and copy again. You will be able to see which ones blend in and which ones stand out. I made a scrap quilt and used cream or white for background and them picked dark and medium to complete the blocks.If you don't need too large of pieces you could fussy cut some of the prints to get dark or light.