I don't think it matters greatly to (most) bees. However, there may be some ...
White is cool in the sun. Not without importance.
White shows the dirt. No bad thing, it has to BE clean, not hide dirt. And it shows any cling-on bees.
But white is very conspicuous, not low profile. Important for some, but not all.
And, for the fashionable, white does look just a little old-fashioned ...
But that sort of consideration doesn't matter much to the great majority of beekeepers, it seems ...
Its a practical piece of protective clothing.
For a beginner, colour shouldn't matter much, compared to its other attributes.
Unless you want to wind up the dinosaurs!