Muscleskins bikinis and thongs are definitely a favorite.

In the mid 1980s I was swimming with the masters group in my local club training sessions. Everyone trained in 2" classic speedos, to race you had to buy the club's 2" royal briefs, I forget who made them. So all the men and boys would be in 2" briefs many of them royal blue.
The junior swimmers had to wear yellow swim caps until they reached a standard where they were awarded royal blue swim caps, this was for safety.
Visiting Carcasson in France I found some 1 3/4" slightly metalic multicolour print swim briefs while shopping and wore them for swim training, no one objected.