There was a trick buried in the two different lighting situations...
The scene's a radiosity nightmare. Nearly everything in that first image is red, and soaked in light. And when you shine a light on something red, you see red bleeding onto everything around that thing. This might not be noticable on their flesh or hair, but their shirts would surely show it.
What you've done with the light values
is very good. Meaning, your picture works in black and white. But the colors still need a little tweaking.
There are many ways to do this, most of which undoubtedly better than what I'm about to show you...
My improvised solution, using your image as a starting point:
Hue/Saturation.. Drop the saturation to -30. Now, things aren't so vibrant, and the flaws that brought about are diminished. It's still not right, though.
Clone the layer your flattened image is on, and go into Hue/Saturation for this new (topmost) layer. Check the "colorize" button. Let's say 40 for hue, 15 for saturation? So, now you've got an aging sepia-toned photo. And it looks pretty good, because again, your light values were right on...
Blend this with your toned-down photo by reducing the layer opacity to, say, 31%.
Now that their colors are all closer together, let's try to set them back to how things looked in the original picture and see what happens. I'm not comfortable finalizing our layers so far, so I create an adjustment layer of type "levels"... I hit the "auto" button to see what it'll do, and adjust from there (mostly changing the red channel - honestly, I think I only dragged two points).
My output levels are all 0 and 255 still. My input levels are as follows:
RED: 7 / 1.14 / 213
GREEN: 15 / 1.00 / 212
BLUE: 14 / 1.00 / 209
...and, I might take the layer opacity (on this adjustment layer) down to about 89%. Maybe. Can't really make up my mind on that one.
The humans in the foreground look a little off now, so let's throw on another hue/saturation adjustment with them in mind. +3/+18, respectively. This actually does a lot for our background action, as well.
Anyway, here's what that ended up looking like:
I'm still not 100% sold on it, but I think the composite's pretty convincing now.
The main thing that I'd like you to pick up from all of that is this:
All of your edits thus far have been made on seperate layers. Which is useful and good, but when you need tight integration, the fastest way to achieve that is with at least one pass on the "final" image as well. (Note that you could have done all of this with adjustment layers and never flattened your image...)
If I were to continue editing from here, I'd make one last change:
Paste in your original image on top as a new layer, setting it's mode to "color" and it's opacity to 20%.
This improves the faces but ruins the shirts, so create a mask to make this layer only affect the faces...