HUE, SATURATION, LIGHTNESS
The original photograph
I first experimented with the individual colors. The Reds muted made the sky pinker. Yellows brought out something of a sunset.
Reducing the Blues made the sky grayer and the addition of more Magents added some purple to the clouds.
Just to see what happened, I used the Master and removed much of the color and lightened the photo. This gave an almost black and white quality to the picture. After working with Hue and Hue, Saturation, and Lightness, I am getting a little bit better feel for the process.