Is there a reason why I can have metal skin on every part of the body but not on the legs? The only way to do this is if the character is wearing full tights or pants. But there's no way to apply metal to skin color on the legs.

Seems like a bug.

I select bare skin/briefs for legs, but the legs are regular skin while the briefs are metal. There's no option to select metal on the legs. The Material - Metal only applies it to the briefs.

So you can have a metal skin face, upper body, hands and feet. But not legs

It wouldn't be an issue if we could select skin colors for the tights, but even that isn't available. Just seems like a glaring oversight.

I just tried it. I was able to select 'metal' for skin material. Used 'tights and skin' and 'skin' then 'metal'. Gave me briefs with metallic skin.