There are many different techniques and ways of creating a selective color images in Photoshop, let me show you the one where we use the black & white adjustment layer.
If you like the Lords of the Rings movie trilogy, then you might also like this Photoshop tutorial, where we will make a dramatically red sky on a random photograph.
Basic tutorial for everyone who want to will learn how to use a dedicated tool for really quick changing of any color you want on a photograph with the help of trusty Photoshop.
Pretty simple and useful tutorial, where you will open a random photograph with smoke and convert it into something really not friendly for our environment.