They have the right idea with the theory, but there's some nuance in proper execution. If I learned anything from photography, it's that the best adjustments are barely on the edge of perception.
If you averaged the before and after examples (allowing that the "average" of colours is a complicated subject in itself), they would probably be pretty good.
If you averaged the before and after examples (allowing that the "average" of colours is a complicated subject in itself), they would probably be pretty good.