Correcting Shots - The Art and Technique of Digital Color Correction - page 308

Fig. 7.71 Second Second-
ary correction, cooling
the sky and warming
everything else.
Fig. 7.72 Data on the correction from inside of the sky qualification, cooling the highlights.
Fig. 7.73 Data on the correction from the outside of the sky qualification, warming the rest of the image in the midtones.