It is simply a uniform for Bnei Torah, as Yidden are supposed to have a uniform”
Who says so? My son is also a Ben Torah, and he wears nicely pressed, clean colored shirts, striped shirts, plaid shirts, solid color shirts, AND white shirts, with beautiful ties, and ALWAYS looks like a real mensch. He is dressed for Shul or work as one would dress for court, or to meet the President. But not solely in white shirts.