I want to make a pattern with only two colors. How would I do that? It's a bit confussing since you have to split the image RGB. And if I only have two colors what would be placed in the Blue image? (is that clear?)

If your pattern only has two colors, you only need to worry about the Red and Green channels. You can ignore the Blue channel. When you set the pattern up in Delphy's tool, you'll specify how many channels it uses.

With a two-color pattern, you really only need to separate out one pattern layer, since it can go on top of a solid background which will be your second color. So make your Red channel solid white, and then in the Green channel put the pattern image (black pixels for the background color, white for the foreground, gray for a blend).

Thanks for explaining!