The skin has a Color Tint setting.

Technical information:

Citizen Version:
Texture set - 2k
LOD0 - 21339
LOD1 - 13154
LOD2 - 4144
LOD3 - 228

Human Male:
Texture set - 2k
LOD0 - 21339
LOD1 - 13154
LOD2 - 4144
LOD3 - 271

Female Version:
Texture set - 2k
LOD0 - 21339
LOD1 - 13153
LOD2 - 4144
LOD3 - 249