How about this: Seems this guy had pretty good style! I like his color choice he wore.
You have good coverage, and an eye for detail - however - the color codes you're using seem to be too vibrant if that makes sense. Try using f5ddcf/ae8b78/c0afa8 for skin, and change the clothes to 'Soft Light' instead of Color (I use this for the Hair too, makes it much easier to pick out a color, and another tip is to click on Background and press Ctrl-L, then making sure the 2 sliding arrows connect to the black areas.), gives it a much more... well, realistic look. Also you have to remember that even though I've done it a couple of times, nowadays with 6 billion people, only about 2% have green eyes. Another thing you have to keep in mind is, approximately half of the soldiers had some variation of blue, the other (approximate) half had some variation of brown, and in between there were a few cases of green and very rarely soldiers would have heterochromia/selective heterochromia (double/mixed iris colors). I'm fairly sure Rutherford B. Hayes had this, since both his irises are different hues of gray in b/w, but it could be the excessive use of lightning in Brady's studio.
I hope I helped and didn't come off as too much of a ******. If you want my collection of color codes which are about 50 different codes, I'd be happy to send it to you.
P.S - forgot to add - if you have 3 different layers (like I color), one Skin at the top, one Hair in the middle, and one Coat in the bottom - Skin has highest priority in terms of overlapping everything else. If you move it beneath Coat (drag and drop), suddenly the Coat has higher priority and Skin won't overlap.
P.P.S - if you have an image with a natural brown color, you can revert this by creating a layer (solid color), choosing the whitest you can go, and then change it's mode to color, save, and re-open in photoshop. Also you can ctrl-A on new layers and press Delete to remove everything instead of deleting it all. Could be you already know this, I've just been bad at photoshop.
