If you decide to keep working on this super cool and charming little paint tool, how possible would it be to have the highlighters have two thickness settings, and clicking them after selecting them flips them between a big highlighter side and a slightly more delicate marker side? I guess the challenge might be animating it, but i suppose just rotating it so that you're using the shorter side of the wedge on the highlighter instead of the long side might work.
It'd help make colouring in stuff a lot easier to handle when I'm not bouncing back and forth between marker and mask to try and get the colour to reach the line, or having to blot down the colour first and outline it after.
in options you can choose the 3 highlighter colours as well as the pen and background. If you also enable transparency mask, thats 6 colours total that you can use.
