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.
In this simple tutorial suitable for the Gimp beginners as well, we are going to manipulate a photograph of standing still car to make it look like it's passing by real fast.
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.
If you don't want others to use your photos and images without your permission, you can create a so called custom watermark with your name or any other text you want.