Here are the light and dark 4-patches. I am working on the 16-patches that will be the transition blocks between the light and the dark (where the white spaces are). I decided to keep track of how long this will take--so far it's been about 12 hours.
I don't know how much I'll like it, but it is kind of fun to do. It's a bit of a mystery--even though I know what it is supposed to look like.