Rotate/Map/Change a selected range of colors, to corresponding range of grays

[Brian.Raila]

Timely assistance earnestly requested.  This HAS to be simple; I am at a loss.

A: See attached –– 'Original - Green Halo'

I seek to Rotate Colors, such that the shaded Greens become shaded grays.  That's it.

I'm familiar with Colors > Map > Rotate Colors... , and can Rotate the Greens to any arbitrary color range.

B: See attached –– 'Edit - Rotated-Color Halo'


There is no end of guidance on the art of manipulating grayscale images into endless variants.  I cannot for the life of me gain insight on the reverse.

Your advice is most gratefully welcome.

– BR

[Ofnuts]

This is just removing the "saturation". Select the screen (lasso in "Polygon" mode, for instance)(you don't even need to be accurate).

The Color>Saturation and set the Scale to 0.

   

[Brian.Raila]

Well I'll be!

To quote Brian.Raila, "This HAS to be simple."

I'd not recognized the notion of "Current Color", being operated on. Yes, I had selected a region, as you suggest, within which to Rotate Colors [using Rectangle Select]. But I'd assumed that subsequent operation therein would affect ALL colors [e.g. the tabletop, wall, flesh].

With thanks, and hats off to Ofnuts !

– BR