Technically that is what they wrote since they forgot the comma. "white, men's briefs" is a list of adjectives describing briefs, the noun. "White men's briefs" makes "white" the adjective describing the men who own the briefs

Men's vs. mens was also an issue that added ambiguity

Sometimes context gives it off, other times you can apply an cheap version off Occam’s razor and just consider that the race version would be absurd and it’s likely the colour of the brief’s

Damn, if only we had some sort of way to symbolize things like this. Maybe small characters we could add to sentences to, i dunno, indicate the way things are related. lol