Does anyone know if theres a fruit that's white on the OUTSIDE and if there isn't why isn't there?

Eggplants are naturally white on the outside. This is why they came to be called eggplants, as they resembled large eggs. The reason most eggplants we see today are purple is due to selective breeding of the plants.

Many squashes are also white, like the Pattypan or White Squash.

Yes, both eggplants and squashes are fruits.