>>717042513
>Ichigio Kurosaki was the only delinquent (yankii) colored of the big four
Yankee is pretty much any brightly dyed hair- including bleaching your hair. Ichigo's strawberry hair is not even the typical understanding of that.
To play off of your erroneous use of "big four" (it's big three for a reason), Dragon Ball outright states what the typical delinquent look is- it's Gohan in the Cell arc. Blonde hair that looks bleached.
There's been a very popular delinquent anime that does the same, all the characters have white or blond hair.