If it should look a bit dreamy or special, then I increase the blue of the sky/ the orange of a sunset/ the tone of the subject for example. See photo 1 and 2.
Normally, I don’t amplify specific colours by default, because I have a CVD and then the pic looks very artificial. It’s more of a special style element that’s used when needed, but not otherwise.
If I want to let the viewer to look at the “contrast”, which I already decreased by a lot, to let patterns or objects pop out more, or give the pic a “depressing” mood, then I decrease the brilliance of one tone. See photo 2
Picture 1: It still looks “wintery and sad”, but the green of the twig is amplified. If the greens wouldn’t be re-compensated, the whole pic would almost be black and white. 1000013077
Pic 2: here I increased the purples a bit and amplified the shadows to fetch the mood and focus of the sunrise DSC06116
Picture 3: still not much contrast, but the almost black&white-look and increased shadows put the focus onto the ice crystals instead of the interior of the barn.
In that way, I can artificially set more contrast, even if I reduced it before. DSC05536