Holly is your best, and probably only choice. But, as said, it isn't all really pure white. I have had success bleaching it. I make a 25% solution of plain household bleach and water and let the wood set in it for a few days. Nothing scientific about concentration or period of time. Vary to suit desired results. Do this before final turning as the water raises the grain.
However, for the whitest, beautifully white, wood, you should look for French, mountain grown, boxwood. Pure as ivory. About as expensive too and, these days, a lot more rare.