When I was little, I used to like filling a sheet of paper with random blocks of bright colors. Then, I'd completely cover everything with a thick layer of black crayon. The next step was to use a toothpick to scrape off a design from the black crayon layer, revealing the pretty colors underneath. Did you guys use to do this too? Now they sell paper that lets you get this same kind of effect, but it's definitely more fun to do it yourself.
I'm bringing this up because it's what came to mind as I blocked out my Hemlock Ring Blanket. The blue blanket looks almost black since it's wet, and that creates a nice effect against the multicolored foam mats I use to block.