I assume you mean the pinkish-grey in the top left corner you could try using a light grey with a red shade over the top. If that's not the area you mean then you'll need to narrow down which colour we're looking at ^^
Edit - missed part of your post where you specify the thighs >.<
tbh it's hard to say as it looks like white flesh (so a white or slightly off-white base) with a very thin red glaze running to the edges.
Edit 3 -
https://www.reddit.com/r/Warhammer/comments/32xxjz/painting_pale_skin/ has a very good example of pale-pinkish flesh, similar to the effect you're chasing