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 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 were ever wondering how the heck do they create those continuous patterns, then wonder no more and check this neat Photoshop tutorial that might teach you a new designing trick or two.