Before

This one I thought was going to be a no-brainer until I realized the purple background had bounced onto the woman's hair. I needed to convert the image to grayscale and then create a duotone to match the parts of her hair that didn't have magenta. Then I combined the original with the duotone. Roll your pointer over the image to see more detail. Scroll down to see the After.

 

After

Roll your pointer over the image to see more detail.