Delinquent Hair

In some cultures, hair dyed unusual colors is considered a sign of delinquency - in the west, this means colours such as blue, pink, green, and similar shades that don't usually appear in nature. In other cultures, where hair shades are typically more similar from person to person, this can include hair tinted or lightened to red or blonde as well. There are certain hair styles which are strongly associated with delinquent or punk behaviour - mohawks, pompadours, certain spiky styles, and a completely shaven head.

In Japanese and other Asian works, this may have something to do with repression of excessive individualism in Asian schools - most evidently in Japan. Of course, this can lead to unfortunate misunderstandings with people who naturally have lighter hair colors.

In Western cultures, unusual hair colors are less strongly associated with delinquency than they were in the past, though they are still more commonly worn by teenagers and young adults than by middle aged or older people - with the exception of the "blue rinse". However, the stigma with certain hairstyles remains, so you would probably still be hesitant about bringing home a punk with a blue mohawk to your parents.

That is, recently. Less than a century ago, dying hair at all was considered a sign of badness, because it was not honest. This is why Hair of Gold is presumed to be natural color while Blondes Are Evil is often dyed. During Restoration England, natural blondes commonly dyed their hair darker because everyone would think they had dyed their hair blond.

This trope usually does not show up in settings where You Gotta Have Blue Hair. See also Blond Guys Are Evil; in the case of Delinquent Hair, it's not that blonde guys are evil, it's that evil guys are more likely to dye their hair blonde. A common attribute of The Quincy Punk, subtrope of Face of a Thug when it's natural. If the hair keeps being re-dyed, it overlaps with Kaleidoscope Hair. Compare Make Up Is Evil.

Anime and Manga

 * Rokudenashi Blues has the entire main cast as examples of this trope. It even becomes the focus of one chapter, where an Evil Teacher makes them change their hair back to normal.
 * In Bleach, Ichigo, a Japanese student, often ran into trouble because of his hair color. He has orange hair, which is what you would get if you bleached Black hair.
 * There's also a hillarious scene when the Soul Reapers show up at Ichigo's school, wearing school uniforms. Ikkaku has his pants rolled up, no socks, and a wooden sword. Renji wears his uniform relatively normal, but with his shirt unbuttoned a bit, revealing the tattoos on his chest, while also wearing a bandanna on his forehead. Onlooking students comment on Yumichika and Rangiku not looking very threatening, and Toshiro and Renji looking odd. Then they point out the scary bald guy. Ikkaku was not amused.
 * While everyone knows that Orihime wouldn't hurt a fly, her hair length and color got her in trouble when she was young, when bullies cut it off.
 * In The Breaker, all the other (Korean) students are afraid of Jinie because of her red hair.
 * Angel Densetsu has a Deconstruction: genuine Delinquent Takehisa has naturally light brown hair. He got a lot of flak for this, so he decided to go the whole nine yards. He dyed it blond and put it up in spikes to be even more delinquent looking.
 * Then an In Universe inversion occurs. Kitano has natural Delinquent Hair and tries his best to make it less noticeable. Then, of course, sensei Hishida tries to "fix" it and this trope is played straight.
 * Later, the trope is played for laughs with the Butt Monkey Ogisu: all the other delinquents laugh at his bright red hair.
 * At the beginning of The Twelve Kingdoms, Youko is criticized for her naturally red hair, and her mother tries to make her dye it a more unassuming shade so that people won't assume she's a delinquent.
 * Sakuragi from Slam Dunk
 * In Fruits Basket, Hatsuharu got into trouble at school for white on top, black on bottom natural hair coloring, as people believed he dyed his hair. On a non-magically coloured note, Arisa Uotani also has lighter hair, of a blonde-brown shade, and was (and is still considered) a delinquent.
 * Kuwabara from Yu Yu Hakusho.
 * In Dragonball Z, after Goku and Gohan achieve Super Saiyan status, Chichi sees them for the first time and are dismayed that they've become delinquents.
 * Shizuo in Durarara dyed his hair blond to differentiate himself from his similar looking (but diametrically opposite in personality) brother, and kind of fits since he has an extreme Hair Trigger Temper and works for loan sharks.
 * It's revealed in a side story that bleaching his hair was Tom's idea: Tom figured that looking the part of a delinquent would deter other kids from picking fights with Shizuo. Shizuo opposed the idea at first (rage disorder aside, Shizuo's about as far away from the delinquent persona as one could get), but eventually changed his mind when he realized just how much Tom cared about his well-being.
 * Masaomi, an easygoing class clown type, dyed his hair blond.
 * Walker might fit too. He definitely satisfied the delinquent part of it, but since he might be biracial, his blond hair could be evidence of Phenotype Stereotype.
 * Miscellaneous thugs in the series, such as those in the Blue Squares, often have dyed hair.
 * In Love Pistols, the Face of a Thug delinquent friend of Inukami has red hair and an outrgeous pompadour. No info whether it's dyed or not.
 * Momo Adachi, the main character of Peach Girl, is assumed to be a slutty kogal as she tans easily and her hair bleached due to her being on the school swim team and thus around chlorinated water a lot. She wishes she looked more like her friend Sae, who is petite, pale, and delicate (but a Bitch in Sheep's Clothing).
 * Kitamura gives it a go in Toradora.
 * Midori Days has a blond delinquent protagonist, though I can't remember if he bleaches it.
 * In Detective Conan, a case is solved because of the differences between the styles of two writers. One was old-fashioned (lovers standing in the rain, separated by a pole was a common scene in his novels) and his delinquents almost always had bleached hair.
 * Also, Kouichi from Bunny Drop dated a red haired delinquent girl, dying his hair red too during this rebellious phase. When he grew out of it, his hair went black again.
 * When Makoto Kino first transfers to Juuban Junior High in the Sailor Moon manga, one of the teachers tells her off for having a perm, until she points out she has naturally wavy hair.
 * Baptistin of Gankutsuou has red hair in a pompadour style.
 * Ran, the main character of Super Gals, continually gets flack from her teacher for having bleached blonde hair with a red streak. During one story arc, she dies her hair orange, and a number of freshmen follow suit, much to the faculty's dismay. In an attempt to stem the tide of ko-gals, Naka-sen promises to cut her summer homework in half if she dyes her hair back. Instead of going back to her original black, however, Ran goes back to her usual blonde style.
 * Discussed in K-On! during its yearbook pictures episode; the girls' school requires students whose hair isn't black or dark brown to bring their baby pictures to prove that their hair color is natural, and anyone who fails to do so is forced to dye their hair before their picture are taken.
 * Sunohara in Clannad has the bleached blond variety (explicitly stated to be dyed, as opposed to a case of You Gotta Have Blue Hair like everyone else). He stops bleaching it when he gets a job.
 * from Wandering Son gets mistaken for this once he dyes his hair from a dark brown to a bright red. It's actually quite similar to another manga by the same mangaka, where a character with a design very much like dyed his hair green.. It only lasts one chapter though.
 * As mentioned above, the protagonist of Shikii No Juunin dyes his hair green. He's a rebellious, matter-of-fact middle schooler who smokes and doesn't want to go to school. Nitori is an Expy of him in design, though due to the different art-styles, it isn't that apparent.
 * Eyeshield 21 has a lot of this. Two of the Ha-Ha brothers and Hiruma are bleached blonde, Agon wears his hair in dreads, and Musashi isn't a delinquent but is supposed to look like one with his mohawk.
 * The protagonist of Boku wa Tomodachi ga Sukunai is wrongly assumed to be a delinquent by most of his peers due to his naturally blond hair.
 * In Fist of the North Star, mohawks are the calling cards of villains whose fate is to be messily killed via martial art techniques that are capable of popping human beings like a zit.
 * Pretty much the majority of the main cast of Beelzebub has this going on. Makes sense, considering it's a series about an entire school of delinquents. Toujo and Kanzaki both have orange, spikey hair.
 * Oga inverts the trope by having brown hair while being one of the most powerful humans in the series. Furuichi also inverts it by having silver hair, but could have gone to the non-delinquent Saint Ishiyama High if not for hanging out with Oga all the time.
 * Himekawa has silver hair kept constantly in a pompadour. He even sleeps with it in the pompadour style.
 * While she's not a delinquent, Eiko from the manga Cousin dyed her hair brown in early high school and started changing in personality.

Film

 * One of the revivifiable Mooks in The Sixth Day has her hair dyed a different color every time she is brought back. She even complains about having to get it dyed (and getting her ears pierced) when revived.
 * The hackers who show up to Neo's door near the beginning of The Matrix all have strange hair colours. They're clearly delinquent-type characters.
 * Subverted in The Boy With Green Hair. Peter is looked on with suspicion by the rest of the town for his green hair, but he just woke up like that one morning.
 * In the Japanese film Akunin, the troubled, violent Shimizu has bleached blond hair, and when Mitsuyo says that she "never expected [she] would be going for a drive with a blond guy like [him]", "blond guy" seems almost like a euphemism for "bad boy".

Literature
"I never knew Eileen to be honest about anything in all her life unless the truth served her better than an evasion. Her hair was not honest color and it was not honest curl."
 * In Gene Stratton Porter's Her Father's Daughter, hair dye is a mark against Eileen's honesty.

Live Action Televison

 * In the Pie in The Sky episode "The Policeman's Daughter", the titular character goes through a rebellious patch that includes running away from home, taking up with undesirable people, and dying her hair pink.
 * Lead character Gentaro from Kamen Rider Fourze puts his hair into a rather prominent pompadour (as can be seen in the opening credits) to complete his appearance, which is that of a stereotypical delinquent...from the 1980s. Despite appearances, he is a friendly, outgoing guy who's stated goal is to become friends with everyone in the school. Does occasionally get him in trouble with the school's would be disciplinarian Oosugi.

Theatre

 * In The Curious Savage, Ethel P. Savage invokes this by dying her hair blue as part of her becoming a Senior Delinquent (in her grown up stepchildren's eyes).

Video Games

 * Persona 4 has Kanji, who, after after years of feeling like an outcast, began dying his hair platinum blond and wearing dark clothes, causing many to think he's part of a gang, as his mother explains to the protagonist.

Web Comics

 * In Red String, Miharu has Bleached Blonde hair and Reika has a perm and her hair is dyed/lightened to a red-brown hue; several people associate them with delinquency - more so Miharu - even though neither of them are. Both of them got restyled together in order to help Reika get over a bad experience. Later, when Miharu is transferred to a more elite school, she is required to dye it back.

Western Animation

 * Duncan from Total Drama's Green Mohawk
 * Though naturally Multicolored Hair is common for the Catfolk of ThunderCats (2011), Wilykit, a young Little Miss Con Artist and Artful Dodger, sports a purple Skunk Stripe.

Real Life

 * According to this article, Japanese students with tinted or long hair have been known have had their hair shorn on the spot by teachers, and one middle school in the city of Kitakyushu once took aside the kids with tinted hair and had staff in a designated area spray it back to black. This was broadcast on a news program.