How do I copy selection from one color layer (let's say - Red) to another?

Question

I'd like to clean up the whites of an eye. In Photoshop I used to select the white of an eye, and copy from Red to Blue and Green channels just by selecting the necessary color channel and clicking CtrlC CtrlV. But in GIMP it not worked.

How can I do it?

Answer 1

In Gimp, in the colors menu, go to components and disassemble them. (Frankly, I do not know the exact wording of the menu items in Gimp's English version). Next you are asked how, go for RGB then. Now what used to be color channels are b&w layers. You can work with each layer and then re-assemble the image.