I've been adding just a touch of the Buff Titan to the Tinting White, and then a smidgen of a gray mix to use for my grays.
Now on to the grays. I also have a problem with my grays getting a little too blue for my taste. I used to use Burnt Umber and Mars Black, with a touch of a yellow ochre, but lately I've been mixing equal parts of Raw Umber and Van Dyke Brown plus a touch of Mars Black. Today I made this little chart of different mixes to see what worked best. I was surprised to see that I liked the mix with the two browns and Ivory Black. I usually equate Ivory Black with blue, but it looks pretty good to me. Mars Black is a stronger tinting color than Ivory Black, so maybe that's why.
You can click on the grays for a larger photo.
So, what do you think? Do you have a favorite "recipe"? I would love to hear what other artists use for their whites and grays when they paint in oils.