Photoshop Expert Interview Question:

Do you know how to achieve Black/White with Color Detail?

Submitted by: Muhammad

use the lasso tool to carefully select the elements that you want to retain as color – you may even want to feather the selection by a couple of pixels if it looks better. Once you have these selected, invert the selection so that everything except the eyes/lips are selected, then desaturated the layer.
Submitted by: Muhammad