Photoshop Tutorial: Colouring intricate parts of an old photo with gradient maps
Colouring an old photo can take some time, its best to work with as many techniques as you can to get the job done. Many people use coloured layers to mask out an area and then paint in the colour. The best analogy i can think of, is that it is like adding to colour with a piece of stained glass above the image. Switch on a light behind the glass and the image is flooded with colour. Paint out some of the stained glass with black and only some of the colour shines through, affecting certain parts of the image.
Gradient maps still use the stained glass analogy s but when the light shines through it uses the dark and light tones as a tool to apply the gradient colour. You can use many colours in gradient map or just two.
This example shows how this technique can be used to colour a tricky or fiddly part of an image.