Saturation and brightness slider affecting code highlighting theme (expandable and generalizable idea)

[RobertBobbinson]

The gist: I want saturation, brightness, and contrast sliders affecting the chosen code highlighting theme.

There are many Godot highlighting themes, but some are too saturated or bright for my taste, and the ones that fit my taste might be too dull for other's. Many themes go wasted for preferences like that, and changing them by hand is cumbersome, so I propose sliders that control those aspects --and possibly more-- of the colors so we could easily create variations of existing themes.

More could be expanded about the idea. I'll just say it could be used for themes in general. Also after the modifications, the capacity to add overriding colors to the color properties of the modified properties could be nice. But that's an extension of the original idea, and I'll leave that for later. Still, just the basic functionality proposed provides a lot of value.

What do you think?