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.
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.