Ok, so. You'll need a text editor, notepad will work, but this will be far easier with notepad++

Open the .sli files I've included with your editor and find the line that looks like this in both:

<skin color0="0.000000; 0.000000; 0.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />

Yours might have slightly different numbers, depending on the default skin tone of the character you chose. Here's where the editing comes in, you replace the numbers that are there with the ones from the skin tone you want your character to keep and save the file, which fixed the bug for me. These are all the skin tones available in the base game, I made this list so you don't have to go searching through game files and testing different number combos like I did. The lightest skin for that head is at the top, and the darkest at the bottom:

Male Faces:

Faces 1 & 2:
Lightest Skin-> <color color0="0.000000; 0.000000; 0.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="0.000000; 0.000000; -5.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="0.000000; 0.000000; -10.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="0.000000; 0.000000; -15.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
Darkest Skin-> <color color0="0.000000; 0.000000; -20.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />


Faces 3 & 4:
<color color0="5.000000; 0.000000; 0.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="5.000000; 0.000000; -5.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="5.000000; 0.000000; -10.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="5.000000; 0.000000; -15.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="5.000000; 0.000000; -20.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />

Faces 5, 6, 7 & 8:
<color color0="0.000000; 0.000000; 10.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="0.000000; 0.000000; 5.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="0.000000; 0.000000; 0.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="0.000000; 0.000000; -5.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />
<color color0="0.000000; 0.000000; -10.000000" color1="0.000000; 0.000000; 0.000000" color2="0.000000; 0.000000; 0.000000" />


Now, I have a mod by Anix107, "Even More Hair Eye Colours and Skin Tones", and the tone I wanted to use was part of that. If you have that mod as well, just open the .sli contained within and you'll see something like this <skinColors> starting at line 474. The second group are the modded ones, and they descend from darkest to lightest.



I hope this was understandable. It took me a bit to figure this out, so feel free to ask me if you need help with it.