I just have to say that I’m very happy that this this thread got necromanced. I could never figure out how the channel mixer in RT worked.
Now I understand what it’s doing, thanks to Pat’s explanation. But I couldn’t figure out the practical application, until I got to @stefan.chirila’s post about making greens look more blue, and it was funny, because last night I was trying to do exactly that, make green plant foliage more blue.
I was messing around with a photo, and only know about the LAB HH adjustment, and the HSV equalizer. I just tried the “channel mixer” technique, and still prefer my results with HSV in this particular picture, but it’s a good tool to know about.