How do I go about sprite work for a random NPC generator?

I'm working on an RPG with 32x32 retro sprite artwork. One element necessary for it is an NPC generator that randomizes their appearances: skin tone, eye color, hair types, clothes and armor, etcetera. One thing I'm tripping over before I've even gotten to the script is how I'll do the sprite work for it.

From my understanding, I have to draw all of the possible sprites/colors and animations for each layer of the complete NPC. For example, the frame and skin tone (Layer 1), eye color, hair type and color, and clothing/equipment. I would then have each sprite stored, randomized, and chosen to be drawn in layers over the object, which would result in the randomized NPC.

So far, I've drawn the character sprites/animations for movement, for each skin tone. So I've got 14 copies of the same sprite, for each skin tone. I know that I could just tint the material of the sprite, but I felt that the quality of the sprite would suffer since it would tint the entire thing, including the little shading details. What I'm also worried about in the future is how I'm going to get the NPC's to do the right animations based on the skin tone they get since there are 14 variations of the same thing. Am I going about this right so far?

Before I move on, I want to make sure I'm not wasting my time with my sprite work. I'm about to get to the hairstyles next. And what I'm expecting from that is to have to redraw the hair for each animation, and then again for each color. I don't really want to continue until I get some type of warning or confirmation.