Take the polygonal Lasso tool and make a selection around your moms hair. It will probably be easier and more precise if your zoomed in on the hair.

Then go to the "Image" menu located along the main toolbar (File, Edit, Etc...).

Proceed to the "Adjustments" tab, followed by selectin the "Hue/Saturation" adjustment tool.

Inside the pop-up window there will be a Checkbox labled "Colorize". Check that, then make your Hue and Saturation adjustments according to your liking.

Click OK, or Apply, I cant remember right now, and BAM, you've just turned your mom into a troll.

Thats as basic as I could come up with.