What you’re describing should be easy to if you use the HSB tab of the existing color picker. HSB is a much better way to deal with colors - RGB is a terribly unintuitive way to represent a color.
Go to the HSB tab, click on the B (Brightness) - pick a color and drag the brightness down a bit - done.
The existing color picker isn’t going away, I’m just making an additional one that’ll have a better form factor for what I need it for in 2d drawing.
