I made a few color schemes while I was bored over the last few months. I've used at least one of them in another pen. If you want to use or remix them, go ahead. If I happen to make more, I'll add them. I made the variants in GIMP by manipulating the blend modes of a layer filled with a color from the base scheme. I forgot exactly who gave me the idea, but it's been fun experimenting with color this way.