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.
Rainbows right? Who does not like rainbows? In this Photoshop tutorial you can learn how to create a rainbow from scratch and add it to any image of your choice.
The new Adobe Photoshop CC introduced quite a few awesome updates to existing tools and feature. One of the most welcomed ones sure is some of the new Image Resize functionalities, check it out.