In the late 1970s and throughout the 80`s it was the norm to wear white y front briefs or starched white baggy shorts but then briefs/pants were the most popular choice of underwear for men.
Then through the 80`s color really hit the undies world and man became fashion conscious about their choice of wear but Y-fronts lost their appeal and the rest is history to coin a popular phrase.
In today's world Tighty Whities really sits well within the gay male lifestyle maybe thats because wearing white briefs is a statement and subject of eroticism who is to say?.
Personally I have many pairs of White underwear especially briefs and yes I find them erotic although I find most pairs of undies I own sensual and a turn on.
Be proud in whatever your choice and color of garment is but if they are white and they are tight(ish) then that`s a bonus.