Most paint brands have a whole selection of 'whites' - all with varying tints in them. Start there, but don't be surprised if you end up with something different than what you expected in order to achieve the look you want. The furnishings, floor color, the direction from which the natural light enters the space, all affect the appearance of the walls.

Have fun, and good luck!

Start with the white base. Add red oxide and yellow oxide, 1/64th of an ounce of each. That's the smallest most tint machines can dispense. You can add more, but that's where to start if you want the faintest peach tint possible.

I was just experimenting with some pale tints. I think that Benjamin Moore white blush may have that peachy tone you want, though it's much more tinted than white. I'd ask the paint store to mix a couple of custom samples -- 50-50% white/white blush mixture and 75-25% white/white blush and see how they look. (Or use whatever other pale color catches your eye.)

I noticed that Behr paints, available at Home Depot, also has a nice range of pale colors. I think they will also custom mix samples.