Most foundations now are neither moisturizing nor oil-control. You'd be better off moisturizing and/or controlling oil in a separate step. On the oily parts, you can apply a thin layer of Milk of Magnesia (yes, the laxative). Let it dry then apply your foundation. It works well, especially if you're fair-skinned.
But are you sure your skin is dry too? That's not uncommon, but I'm asking because you say you have dermatitis (seborrheic, right?) and that can look like dryness even when it's not. Actually, seborrhea could be an overproduction of sebum/oil and an abundance of yeast. Basically it's dandruff of the face. So your skin can flake, discolor and look irritated. But that doesn't mean it's dry. Do you use anything to treat the seborrhea? If it really is dryness, I'd apply a moisturizer under the foundation. Try Embryolisse or possibly coconut oil, argan oil or jojoba oil also.
For yellow foundations, I like Becca, Kevyn Aucoin and Valana Minerals. I've also seen good reviews of Youngblood Liquid Mineral Foundation re: their yellow tones. I'm very yellow/olive and Mac is way too orangey for me too.