Can we skip on the cold seme and the energetic uke already? I don't wanna read something l...

Same here, I don't like cold seme boys... And that's right! They usually are black haired, don't know why!

Because it's black. The color black can be associated with evil, death, and mystery yada yada.

That's the plot of "I'm dark, my past is dark, my hair is dark, everything is cold and dark about me."

That's so much boriiiing...

If you wanna, I'll give you some clichés (in mangas, not Manhwa. They have clichés too but they're not related to the Color hair):
Blond haired uke? Light, innocent, energetic, likes women and completely clueless.Aka, not that smart.
Black haired uke? Slutty OR country bumpkin. If slut, then has a lot of trust issues with men and has a difficult pass that they are hiding under their slutty mask (Well, slutty or not, that isn't mandatory but they'll have trust issues). If country bumpkin, then is completely naïve, clueless and lacks severely of self-esteem.

Black haired seme? "I'm so daaaaark, my life until then was so daaaaaaark, I'll be a complete asshole but you're gonna heal me."
Blond haired seme? Puppy seme. Joyful, happy go lucky type. Not that smart, too. OR it can be the popular type (of the company/high school/college) and if it's the case, he will be cool, loved by anybody and will be smart. If popular type, he can be a slut too, that depend. But if he is a slut, it is all about some crapy background like "love is so bothersome" which will soon enough evolve to "I can't get hard for anyone else than you anymore."(Bitch, PLEASE.)
And grey toned haired seme are the sport type.

That's about it.
Oh, and I'm only describing short haired characters. It's not the same if they have long hair.
Long hair on a seme means:
if black: They're a little unkept and don't care anymore about their apparence (cause: They're getting old, are working at home or had an heartbreak) the lonely type.
If blond: they'll be some kind of god related existence most of the time. They can be kind or not, depend of the story. (man, as I am writing that, I have so many yaois flashing through my mind.) It can also be because of crossdressing. (Never saw a long black haired seme crossdressing before so I guess, they need to be blond or grey toned.)

Long haired uke isn't that much of a thing so I'm not gonna say lots on it but blond haired uses are mostly here to antagonist the uke of the Main couple. If it is, then blond haired second uke will be slutty, mean and overly sexual and feminine, to make a good antagonist.
Long black haired uke aren't really such a style... They'll be gay, involved in the night scene most of the time. Can cross dress or not.

Sometimes, I stumble against a black haired seme who's not being completely rude from the beginning or a main slutty uke with long or not blond hair. It IS refreshing.

Oh, and for black haired uke: If slutty: they're gay. If country bumpkin: the seme will be their first love.

Thanks a lot!

You are right, these clichés are accurate most of the time in BL manga

I like reversible couples the most, manly and dark haired ukes as well

It’s honestly kind of exhausting how formulaic and uninspired the genre is overall. And any attempt at change it mainly met with resistance.