I have this shot which has the right door color corrected to make it look dark and red :
How would I go about making it part of the "background" so that when someone comes in front of it, he is not affected by the correction like in the shot below :
I tried looking into Masks as background or 3D layers but couldn't seem to find what I'm looking for. I'm sure it's an easy thing to do but I just need guidance on what to look / search for.