Selective Colour
An adjustment that targets one range of colours in an image while leaving the rest unchanged.
In depth
Used with restraint it is one of the most useful correction tools available: pulling the green out of foliage reflected on skin, or separating two similar blues in a sky. Its notorious form — a monochrome image with one object left in colour — is a stylistic effect that dates quickly and rarely survives more than a first glance.
Examples in practice
Targeting only the yellow-green band lets grass be deepened without shifting a subject's skin tone at all.