Colorizing is a good thing to know using photoshop. It's one of
the basics and if you don't know much about it yet, then maybe this
tutorial will help you.
1. First open your image. Mine here is Angelina Jolie.
2. Then open the Hue/Saturation dialog box (Image > Adjust >
Hue/Saturation or just press Ctrl + U).
Be sure you check the Colorize at the
bottom right.
3. Then adjust the Hue and Saturation. Here are the samples:
Soft
Brown (Hue= 0 / Saturation=25 / Lightness=0)
Yellowish Brown (Hue= 31 /
Saturation=35 / Lightness=0)
Green (Hue= 128 /
Saturation=35 / Lightness=0)
Blue (Hue= 200 / Saturation=35
/ Lightness=0)
Strong Blue (Hue= 238 /
Saturation=35 / Lightness=0)