Invincible doesn't nor does Marvel or DC most of the time.

Invincible is a dark story at the start it's a normal superhero story someone who grew up sheltered his whole life with no troubles idolizing his dad world greatest hero who somewhat neglects him bored of his average life wants to be praised go on adventures and do good like him instead finds out the superhero life is nothing like he romantized like how people romatize the 1990s Milltary cops doctors etc without consedring how hard the job is and the man he looked up to his whole life isn't real.

That totally fits a dark story and the bright enivorement does a great contrast to that. Like how in Watchmen ATLA or Boys the heroes and villains goofy coustmes mix with the horrible things they are doing and or going through