It's a process of separating the image into the separate channels of R, G and B. From there I added a color burn to each of the separate layers. I had to look up a few tutorials but half of the learning comes from finding out on your own, so I would take up the challenge as well!
You should be able to duplicate the layer and delete the channels you don't want. So to show green, you would delete the red and blue channels. In gimp there is a channels tool and appears photoshop has one also.
https://helpx.adobe.com/photoshop/using/channel-basics.html
You should be able to duplicate the layer and delete the channels you don’t want. So to show green, you would delete the red and blue channels. In gimp there is a channels tool and appears photoshop has one also.
https://helpx.adobe.com/photoshop/using/channel-basics.html