Do you want a realistic look or something according to the 'red man' cliché?
For the first just paint them like average Europeans (not as light as Caucasian skin). Most Woodland Natives only seem to be 'darkened' by being outdoor most of the time. There's nothing 'red' about their skin colour, 'bronzed' at best.
For improved differentiation on the tabletop maybe use a pale brown. I've also had my issues, but after looking at hundreds of photos I ended up with Foundry's "Dusky Flesh" (here's an example:
LINK). Perhaps one could build this up on a reddish base colour like "Chestnut".