Colouring walls is a fun trend right now. I'll be honest: I'm not sure how I feel about it. When I know something has been changed drastically in my image, I have a hard time shaking the idea that it looks fake. Truth is, though, I often like it in others' images. Sometimes I can't tell whether the wall has been coloured in post or not.
So I tried it myself. And I'm offering you the easiest step-by-step on Corel Paint Shop Pro. Not too complicated. Basic tool use. Keeping it real, guys.
Duplicate your layer...
Selecting your top layer, go under ADJUST in your menu. Select Hue and Saturation. Choose Hue/Saturation/Lightness...
Adjust your hue, mostly, fiddling a little with the saturation and perhaps even the lightness until you get where you want to go. Select and de-select Preview on Image to decide if you like how the colours meld together.
Starting with the center of the subject, start erasing the subject. Move from a larger, harder, more opaque eraser, and as you get into the finer details, switch to a softer, smaller, less opaque eraser.
For wisps of hair, reduce your brush opacity way down. In this case, I moved mine to 7. And increase the size. You will see the colour of the hair, and its details, start to peek through as you very slowly work the brush with fluid motions. Don't use choppy movements, trying to outline the hair.
Check on your layer opacity. Would your image benefit from bringing down the opacity of the modified layer a little? I felt mine needed to come down to 90%.
After flattening your image (merging all your layers) a filter all over can really help to marry the real with the modified. I like to go into EFFECTS, under Photo Effects, to Film and Filters. I keep it simple, and the filter colour (with no effect) is generally a dark brown, at a density of 10. It makes just enough of a difference.
Hope you are now brave enough to try this yourself!