I recently saw this painting in person, and let me tell you, nothing about this seems un-masculine to me. Louis XIV here is straight-up rocking tights, red high heels, and Brian May's exact hair, but damn if he's not pulling it off. Who's going to laugh at him? Nobody, that's who. Dude's got a freakin' sword and a sassy pose that practically screams, "I can't wait to eviscerate the first person to criticize my cloak's hemming."
So why is it that today, even introducing some bright colors to the standard suit and tie will make you too flamboyant for the average conference room, where the only acceptable colors for men's clothing are basically "black" and "blue so dark that it's basically black"?
I Blame A Guy Named Beau Brummell
Beau Brummell was a sartorial luminary of the 19th century who was the best representation of the burgeoning dandy movement. Brummell's style rejected breeches, brocades, and vibrant colors in favor of blacks, grays, and clean lines. He thought men should wear a white shirt with a dark jacket, matching pants, and a tied neck ornament. In other words, he more or less popularized what would become the modern suit.
Richard Dighton - Public Domain