Thats not how it works…Think of it this way… if you have a two pixel values one where the green is lower and one where it is higher…Then adding Red in the green channel will make a change only to red but proportional to green of the pixel value …you can do the math for any pixel… In the sub groups you change only one channel red, green or blue but you do so in proportion to the value of the input channel that you choose times the multiplier… so if for example a pixel has a blue value of 0 or very low and you try to add red or green or blue to the pixel based on that input it wont’ do a thing…ie the RB slider the GB slider and the BB slider…
Its well explained here…
The Channel Mixer.pdf (68.9 KB)