Controlled vocab useful for describing skin tone

Howdy all,

I'm trying to wrap my mind around an image project that allows clinicians
and students to see how different medical conditions visually manifest
themselves on different skin tones and types.

I suspect we'll use ICD-10 to describe conditions, but I'm curious as to
what recommendations people might have for a relatively simple skin color
vocab. It's conceivable to SNOMED for that, but the terms are very broad
and the terms are driven by race more than color.

Any suggestions would be appreciated. Thanks,

kyle