You have to create new layer on top of the original layer and color it with the brush tool and then adjust the blending modes.
Select separate parts of the image , and then change the or modify the RGB curves, Some R and D on that and im sure it will yeild good results
Actually follow the steps and you will find the right direction. Go to New Layer option. Or Click on Icon to create new layer. Thanks Choose the color mode. Hope you got the idea. Thanks
i hav tried this.. jus select the parts of the picture.. and colour it. then adjust the colours using hue and saturation option... it worked well
Every suggestion here is almost right but don't forget to change your image mode to RGB as it make color editable. You may change once you think you have finished.