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.
There is an unlimited number of ways to create amazing looking effects using Photoshop and its filters, let me show you how to create a mysterious looking one from scratch.