This as my first tutorial, so I’m sorry if its clunky or poorly-written.
This is about keeping your game(s) small, by combining RGB channels from different images. Its primarily written for BGMC (Your game has to be under 12 Megabytes) but others may find it useful for different projects too.
Gather your Images.
I’ll be using my profile pic, and two screenshots, but you can use any images. (Like textures. Keep in mind this works best for textures like rock and grass, where color is more-or-less uniform throughout.)
Open GIMP. Put all of your textures in 1 images as layers. The must all be the same size, but you can use GIMP’s scale tool to do that. I’ll be using 512 X 512.
Use the “Desaturate tool” on all three images. (Colors -> Desaturate) All of your layes should now be greyscale.
Set the opacity slider (on the top of the Layers menu) to 50% for the top layer and second layer. Only the bottom should be fully Opaque.