return to dressing like rich medieval europeans

In fire the red and yellow would be camouflage.

At Worf's trial fir his father's honor the Klingons literally call it a child's uniform.

100% they make fun of them.

I always wanted to see a species that communicated in light patterns. I imagine aquatic species might do this.

Although, let's not omit that in the 1800s, indoor plumbing hadn't been quite a thing yet. In fact, it wasn't until the late 1820s (?) that fancy hotels and civic buildings had it installed, before moving on to municipal works. It didn't become common in residences until nearly 1900.

"Drab"? Nah, dingy 😅

Well, there's things that never will be right, I know
And things need changin' everywhere you go
But 'til we start to make a move to make a few things right
You'll never see me wear a suit of white

Ah, I'd love to wear a rainbow every day
And tell the world that everything's okay
But I'll try to carry off a little darkness on my back
'Til things are brighter, I'm the man in black

Johnny Cash - Man in Black

Drabness of the 1800s? My girl, have you looked around recently? Millennial Grey is mild compared to current fashion.