Somehow, this is why we'd need the Fallout engine to have support for various palettes, or colors for various critters. If that was possible we wouldn't need to make seperate graphics for folks with dark skin, instead their skin color and hair gets tinted so we can have any ethnicity and hair color.
…Though that may only happen in Falltergeist, since this engine is old and robust especially after Black Isle Studios went taking the source code with it.