Photographer and educator Jeff Rojas has been producing a great series of quick photography tips and tutorials over on his YouTube channel for some time now, and in one of his latest videos, he tackles this very issue. So if you have been struggling with how to add some color to your backgrounds without pulling your hair out, Rojas has you covered.
The first step, as Rojas explains it, is in creating a clean selection of your background. This is what will facilitate the color adding process, allowing you to add color to your background without it affecting the color on your subject. To do this, you can use the selection tool in Photoshop to choose a Color Range, and from there you can select the color of your background, and Photoshop will take care of the rest.
Once you have made your background selection, the process of adding color is as simple as adding a curves adjustment layer to your image. Then you can play with your RGB curves to add the color of your choice into your background. In the case of this video, Rojas chooses to add a little pink tone into his background to complement the rosy cheeks of his model.
Finally, you can use a black paintbrush, used on the curves layer, to paint out the color effect from any areas of the image where the background color change has affected it in ways you do not like or intend. (pink eyes are an obvious example)
So there you have it — a quick and painless method for adding a splash of color into your white/grey backgrounds in Photoshop. Make sure and check out Jeff Rojas over on YouTube for more great videos like this one.