Open a hue/saturation adjustment layer above the background layer
In the drop-down, select "Reds" and move the hue slider to the right. Work the saturation and lightness sliders as well
In the drop-down, select "Master", then try to further improve the picture with the sliders.
Note that you have a mask associated with the adjustment layer. If you don't want the resulting changes applied to a portion of the picture, left click the mask (the white rectangle), then paint with a black brush where you don't want the changes. If you go too far, you can reverse the process by painting with a white brush. [Black hides, white reveals]