Here are a couple not so good pictures of my experiments in painting white, a Wolverine and a Longbow in 10th Pesht Regulars
I like how the Longbow turned out better than I like the Wolverine.
For the wolverine I started out with "Dirty Linen" which is kinda a butter colored and then added white. It's a little too yellow for my tastes.
The Longbow is white with a Ghost Grey wash, but it didn't work as well as I wanted.
I'm much happier with how the green and blue highlights turned out. Too bad you can't really see them in these photos.