Color Manipulation ToolKit

[MorrowShore]

Drawpile could use a color manipulation tool.

If we're going for it, might as well go for an extremely potent one. Live preview is imperative to such a feature.

Here's a mockup of what it would look like:

In effect, it's a compilation of various tools already present in GIMP:

[amoruwu]

Made a image for how it might look like.