Yes, this is the place. You need some basics knowledge about glsl. Tibo, I'll make a PR asap(in the weekend), and you will check the "basics". In two words, firstly create user interface (input point), property setter etc. in the plugin, such as set startColor etc. then create shader uniform for the colors, in the shader inside the plugin, and voila, you can change the colors. It's easy, but need some basics. I'll show.