I got this from the book photoshop for dummies, such as myself. I wanted to create something a little different in an otherwise a dull shot.
1. After your final image editing process, create a new layer
2. Combine the previous layers into the new layer
3. Choose image-Adjustments-Hue/Saturatio
4. From the edit dropdown list, choose reds
5. Move the saturation slider all the way to the left untill the amount reads -100
6. Repeat the same procedure for all the colours, yellow, greens, cyans,blues,magentas
7. try moving red or another colour back to bring out a colour in the photo
If anyone has any other ways of doing this better please let me know.