Choose COLOR as the mode to your brush. Create a new layer (FOGY).

And begin to paint the fog. I'm also using a ripped edged one.

photo effects



photo effects

photo effects



And some color to the fog and for and the image corner area. Use soft low flow brush.

photo effects

photo effects

Now I will ad some color to the uniforms of the soldiers. I don't really sure that they were green. But I want them to be green.

So I'm just picking a most simple
 
brush here, setting the flow to about 30 – 50 % (depending on the tablet you use), setting the color mode to COLOR and toggling it to normal some times.

photo effects

photo effects

photo effects

And the final step: a little bit of Color balance and some noise.

photo effects

photo effects

And we are basically done. So I hope you learn something. Don't be afraid to color the photos.

photo effects

Enjoy.