Rapunzel, like most Fairy Tale heroines, is illustrated with Hair of Gold.
On the day that you were born, the angels got together, And decided to create a dream come true, So they sprinkled moondust in your hair of gold... — The Carpenters, "Close to You"
The character is a blonde. Therefore, obviously, she is beautiful, good, young and innocent. Sweet, wholesome, kind, and feminine tend to be included, and the innocence can range up to Virgin Power.
Men falling under this trope are rarer, but the blond hero can also have Hair of Gold. Such a hero is more action-oriented than the Hair of Gold heroine, but he is also good, wholesome, kind to those weaker than himself, modest, and prone to be the Chaste Hero or Celibate Hero.
A prevalent trope wherever blond hair occurs naturally in the population. (Where it does not, Evil Foreigner tends to trump the color.) Since hair tends to darken with age, blondness does correlate with youth, and the innocence is correlated with that. Fiction runs with this so that the women are Colour-Coded for Your Convenience.
If she's obviously beautiful but too mature for childlike innocence it's Everyone Loves Blondes.
Often contrasted with a dark-haired heroine — as the Betty in a Betty and Veronica, the Girl Next Door compared to the Femme Fatale, the Damsel In Distress rather than The Vamp, the Country Mouse instead of the City Mouse — or just lacking the brunette's Jade-Colored Glasses. A redhead may also contrast, and serve as a rival, though she will likely be more action-oriented than the blonde. She tends to be the younger of the pair; this is even more likely to be true for the male version.
The blonde's youth may also make her more naive than her counterpart, which can, but does not have to, slide into the Dumb Blonde. On the other hand, she may regard studying and doing well in school as part of her responsibilities, and so perform better than her dark-haired and irresponsible Foil.
Victorian literature would also use it to portray her as delicate and fragile, if not actually the Ill Girl — being, of course, Too Good For This Sinful Earth. This part would be a Discredited Trope if it were not a Forgotten Trope. An interesting point is that this usually isn't true everywhere: Most Scandinavian stuff seems to connect the Ill Girl stereotype with dark hair.
The trope generally presumes blond is the natural color, since the correlation with youth no longer holds once dye is used. Indeed, this may drive this trope's interchange with Blondes Are Evil, a deeply Cyclic Trope.
When blondes are natural, blondness does correlate with youth and so is attractive. Women therefore dye their hair blond. But after a critical mass of blondes have dyed hair, it no longer correlates with youth. And it certainly doesn't correlate with innocence; the honest brunette who does not dye her hair, perhaps because she is not scheming to get a man, appears more innocent. Therefore blond hair dye falls out of fashion and then blondes are once again mostly natural blondes and so the correlation recurs — restarting the cycle.
When the cycle is on Hair of Gold, lack of blond hair may convince a woman or girl that she is not beautiful — leading to Beautiful All Along.
Women with Hair of Gold are also prone to Blue Eyes, or Gray Eyes (though this is less common in more recent times). This contains a certain amount of Truth in Television, but it is exaggerated in fiction. They also tend to have voices in the soprano range.
For even lighter hair, see White-Haired Pretty Girl.
All inversions belong in Blondes Are Evil.
Not all blondes belong in this list. Not even all good blondes. If the character does not match the personality type, she does not have Hair of Gold and should be listed only if she exploits the expectation. When blonde characters are popular and fun-loving rather than innocent, it's Everyone Loves Blondes.
Janine from Animerica symbolizes this in every purest form imaginable, making her a direct contrast not just to her Love Interest, but to the black-haired Lita and the red-headed Malin. In fact, just about every blonde (except for Takuya and Shirogane) in the series symbolizes this.
Several girls from Mahou Sensei Negima! qualify, most notably Evangeline, and Arika, Negi's mother.
All kirin in the series The Twelve Kingdoms, with one notable pale-skinned and dark-haired exception. But even the exception fits the trope's personality.
Soul Eater has a very interesting version with its girls: Maka Albarn's blond hair has hints of silver (and she is the wisest), Liz Thompson has a caramel blond coloring (she is the most jaded, though remains optimistic), and Patti Thompson has cornsilk coloring and is the sweetest and most idealistic of the three. Justin Law at first seems to follow this, being a chaste (or so we think) young death scythe. Unfortunately...
What, no mention of Marie Mjölnir?
Project A-Ko: C-ko, who is a strawberry blonde, was described in one of the original Japanese promos as "innocence personified".
Not even a demon can find much fault in Elizabeth in Kuroshitsuji. Even if she did probably lose any Virgin Power she might have had.
Oz from Pandora Hearts may or may not fit this trope, but Jack sure does. Vincent, on the other hand...
Ouran High School Host Club has Tamaki, a boy who has a very optimistic view on life, despite his own past and present hardships. He tries to see the good in people, and like a true romantic, thinks every woman is beautiful in her own way. Despite him being The Charmer, his views on love are quite innocent and old fashioned. Honey would fit this trope, as well, especially considering he even LOOKS a lot like a child, although he's actually the oldest of the Hosts. He also carries around a bunny plushie and has a love for sweets—cake in particular.
Belldandy of Oh My Goddess! fits the personality aspects of Hair of Gold very well— though she's more of a dirty-blonde, and began the original manga with silvery hair.
Fullmetal Alchemist's Edward Elric is a male example - although he can be a jerk at times, he has a heart of gold, absolutely refuses to kill people or to use Philosopher's Stones, and is a Chaste Hero. His brother Al fits the personality type even better.
Yuri Genre series often favor this trope for the Uke role:
Several characters in To Aru Majutsu no Index, such as Vento of the Front, Oriana Thomson, and Aiwass. Vento of the Front is an interesting case, since her appearance is described as that of a holy virgin, but is ruined by her self-presentation.
One of the rare male examples that fit this trope perfectly is Keith Goodman (aka "Sky High") from Tiger & Bunny.
Ballads
Many Child Ballads describe the hero or heroine as having "yellow hair", at least in some variants:
In Sir Patrick Spens, the ladies may wait "Kembing down their yellow hair".
In some variants of Famous Flower of Serving Men, both the heroine's loves: the murdered husband ("And don't you think that her heart was sore as she laid the mould on his yellow hair") and the king (" they tangled all in his yellow hair")
Blond hair is very common in Marvel Comics due to inking — the easiest colors were blond (just use yellow), black and red. Red hair tended to go to female love interests; black hair was somewhat more likely to go to bystanders and villains; brown hair, as it involved mixed inks, was fairly rare. Naturally, by now this isn't an issue, but characters who've been around since the 1960s keep their old colors.
DC Comics (see below) averted this trope big time with the Big Two (Superman and Batman both have black hair), but it got a bit out of hand with the Justice Society of America: the Golden Age Hawkman (Carter Hall), Doctor Fate (Kent Nelson), and Green Lantern (Alan Scott) were all blond, as were Johnny Thunder and later members Dr. Mid-Nite (Charles McNider) and Mr. Terrific (Terry Sloane). Interestingly, the Golden Age Flash (Jay Garrick) has (almost) always been one of the rare brown-haired characters.
Consider The Avengers: Out of the early roster, Hank Pym, Thor and Captain America were all blonds. In Cap's case, this trope fully applies: He's wholesome, is a good man and blushes at praise, but in others it really makes little difference.
It's older than Marvel. The hair color problem has been around as long as four-color "funny papers".
You forgot Hawkeye, Clint Barton, who showed off his blond hair when he became Goliath for a while. Of course, Clint's a former villain, a wiseass and always saying he could lead better than Cap, so he's an inversion of the trope.
Clint Barton is addicted to Clairol. His hair has been every color from platinum blond to jet black.
Speaking of the Avengers: The Sentry also has Hair of Gold, and keeps his long, in order to stand out amongst the other blond heroes (except for Thor, but he was dead at the time...)
In the Marvel comic book adaptation of Robert E. Howard's Conan the Barbarian story "A Witch Shall Be Born", Queen Tamaris fits this trope. Her identical twin sister, the witch Salome, fits the Blondes Are Evil trope.
In Non Sequitur, the blond Kate is the more optimistic and less ambitious Foil to her black-haired sister, Danae.
In Peanuts, Charlie Brown's little sister, Sally, fits this trope. When accused of "evading responsibility" by her brother, she responded with, "I don't know what you're talking about...I'm too young and innocent."
The Fair Folk found blond hair so attractive that both babies and women with this color of hair were much more likely to be taken.
Occasional fairy tales explicitly describe the heroines as blond in the text, such as The Myrtle, The Goose Girl and Fair Goldilocks. But Victorian illustrators would depict them as blond except when they were explicitly described as not blond in the text. Which is to say, Snow White didn't get drawn as blond (and sometimes even she does).
The Bulgarian folk fairy tale The Golden Girl has the main blonde heroine turn all golden.
Goldilocks combines both the innocence and the folly associated with blond hair.
Films — Animation
Disney is often accused of favoring blondes, even though the majority of Disney heroines are brunettes and, between 1959 and 2010, Disney never had a blond female lead.
Aurora from Sleeping Beauty is a straight example, her golden hair being a gift from a fairy.
Cinderella was actually titian haired in the original film, but merchandise usually makes her hair bright yellow.
Tinker Bell, but only in the Disney Fairies franchise. In Peter Pan she is definitely not innocent.
Princess Eilonwy, in the film adaptation of The Black Cauldron, is given almost washed-out blond hair ...despite the source material stating explicitly (and repeatedly) that she's a redhead.
Played straight with Rapunzel in Tangled, as she is sweet, kind and innocent. Subverted when we find out she is actually a natural brunette when her hair gets cut off.
Princess Melisande of The Flight of Dragons is a rather Disneyfied version of the trope.
Miguel from Road to El Dorado is a male version, despite being a thief for a living. His lack of actual innocence is made up for by his genuine sweetness and optimism about the world in general. Overall he's a really good person who isn't above using puppy eyes to get his way.
Films — Live-Action
Following the frequent book descriptions as "fair-haired", in the 2003 and 2005 film adaptations of Pride and Prejudice, the prettiest (and most innocent) daughter, Jane, is a blonde. She isn't a blonde in the 1940s film, though.
Both the movie and the stage play made a big deal of this. Johanna got this from her mother Lucy, who is described by Sweeney as "beautiful" and "virtuous" at the start of the whole thing, if something of a "silly little nit" according to Mrs. Lovett. Of course, in the stage play, Johanna gets one of the two kills that Sweeney doesn't get when she guns down the asylum keeper Jonas Fogg.
Amy Kane (Grace Kelly) in High Noon. Initially portrayed as innocent and naive, she proves to be the only person willing to help her husband fight the villains.
Manon of Manon of the Spring (Manon des Sources) is proud, beautiful, and no man's fool — but she is also good-natured at heart, and righteous. Her role, in juxtaposition to the other characters, is basically purity personified.
Kim in Edward Scissorhands is a Double Subversion. She's first seen in a family photo where Peg describes her as her pride and joy. When we meet Kim however she seems like a bratty teenager. But as the film goes on and she warms to Edward we see she is kind and caring, thus fitting the trope.
Literature
In George Eliot's Silas Marner, Silas finds Eppie, a little blond girl, asleep on his hearth. At first he mistakes her blond hair for gold stolen from him, and this plays into his decision that he will raise her.
In Gosick, Victoria's hair is mentioned a lot. It's blond.
In the His Dark Materials series, the mostly evil Mrs Coulter has black hair, and the always good witch Serafina Pekkala has blond hair. This was reversed in the film.
In C. S. Lewis' The Chronicles of Narnia, the innocent Lucy, who first finds Narnia and is closest to Aslan, is described (near the end of the first novel) as having blond hair. However, the illustrations by Pauline Baynes show her with black hair and pigtails. She is also not blonde in the various film adaptations.
Frances Hodgson Burnett's A Little Princess invokes this. The heroine's convinced that she's unattractive ("I am one of the ugliest children I ever saw"), because she doesn't have dimples and golden curls, even though the narrator assures us that she is "a slim, supple little creature" and has "big, wonderful eyes with long black lashes".
Which makes it pretty ironic that in one of the movie versions she was played by Shirley Temple.
In The Secret Garden, Mary has "yellow" hair, but it's played as ugly, stringy and sickly looking, often mentioned in conjunction with her sallow skin. Presumably this changes after she learns to play outdoors and gets healthier.
Tamora Pierce consciously averts this. She has stated that none of her heroines is blond precisely because of this trope, and in Song of the Lioness, the blond woman, Josiane, is the evil one.
Many heroines later, she's finally relented with the Provost's Dog books — Beka has dark blond hair.
In The Clique novels, Claire Lyons has light blond hair, and is the nicest member of the Pretty Commitee.
Jane of Dick and Jane, the baby sister Sally, and Mother all had blond hair.
Queen Ehlana, ruler of Elenia in the David EddingsElenium novels, is described has having a "wealth" of golden hair. The trope is inverted in the same series by her aunt, Princess Arissa, who has equally blond hair and is The Vamp.
Elayne Trakand from the Wheel of Time series has a mass of "sunburst" curls.
This is very common for the heroines of Roman-era Greek novels, including the female lead of Theagenes and Chariclea, despite the fact that she's an Ethiopian princess.
In Jim Butcher's Dresden Files novel Grave Peril, two vampires' dangerousness is contrasted with their Hair of Gold, their Blue Eyes, and their tennis whites.
Both Laurana and Goldmoon in the Dragonlance books are beautiful blond princessess (elf and barbarian human, respectively). The former was naive and self absorbed to the point of being an airhead while the latter was a haughty ice queen worshipped as a goddess by her tribe. They both grew out of it into an Action Girl and The Messiah, respectively.
In James Swallow's Warhammer 40,000Blood Angels novel Deus Encarmine, Arkio's blond hair makes him look like their primarch, along with his courage and his leadership. Which is part and parcel of why they accept him as the Reborn Angel. A Chaos-inspired lie.
In the Demon Princes, Alusz Iphigenia Eperje-Tokay has dusty blond hair and Grey Eyes. She's beautiful, intelligent, gently bred and fatalistic.
The title character of Jane Austen's Emma is interested in befriending a girl of lower social standing than herself, Harriet, specifically because of Harriet's beauty — she has Hair of Gold and big Blue Eyes.
In Goblin Market Laura's golden hair is a key part of the plot, because she buys fruit with "a golden curl" rather than with actual money. Using her hair this way leads to the loss of innocence (and, metaphorically, her virginity).
In The Silmarillion, this is the hallmark of the House of Finarfin (the more innocent, wise and spiritual house of High Elves. One of those elves (Galadriel) even lasted long enough to appear in Lord of the Rings.
Glorfindel's name translates as this in Sindarin ("Elf with Gold Hair").
And lets not forget about Vanyar in general.
Princess Goodness, from The Dragon Hoard is said to have hair that is "just the colour of summer sunlight" in the first chapter and "bright golden as a buttercup" in the last.
Inverted in Doctor Who with the Sixth Doctor, who had curly blond hair, and yet was the most anti-heroic incarnation.
Though played straighter with the much gentler and equally blonde Fifth Doctor.
Prince Arthur in Merlin. Although, at first, it's almost Foreshadowing because initially he looks like a hero, but acts like a Jerkass. However, his eventual Heroic Character Development is a foregone conclusion, since he's eventually going to be King Arthur, who is pretty much the archetypal good guy of all time. And the series is doing a nice job of depicting that journey, so far.
Combine with those startling Blue Eyes of his and you most definitely have yourself a hero.
YMMV but his counterpart in Camelot seems a less successful attempt. Has the right colouring, but arguably the least heroic male main character in that show. The potential for futureCharacter Development may have been there, but by the end of that show's only season, he was still quite bratty and didn't seem to have learned much.
Daniel Jackson of the Stargate Verse generally falls under this. He's usually the first to give anyone the benefit of the doubt, is The Heart of the team, and is probably the youngest on the original team as well. He's prone to Heroic Sacrifices.
In Victorian flashbacks, Sanctuary's Helen Magnus has long, curly blond hair. She's also more soft-spoken, cheerful and younger (obviously) than in the present. Sometime after discovering her fiance is Jack the Ripper and being contracted by the Crown to kill Adam Worth, she goes brunette.
Henry VIII sees Jane Seymour as this in The Tudors. In season 3 it becomes clear she has a little more depth, but Henry reacts aggresively to any indication that she doesn't agree with him. When she returns briefly in season 4, she's the only ghost Henry seems happy to see. Unfortunately for him, she is not as meek as before.
Truth in Television, at least in part; blonde Jane was significantly more tractable and sweet than her tempestous, brunette predecessor Anne Boleyn.
Don "Doc" Dogoier of Kaizoku Sentai Gokaiger stands out among his crew of pirates for being kind, gentle, shy, cheerful and a pacifist - even more so than supposed Token Good Teammate (and dark-haired) Ahim, who has proven herself to have a devious side that Don doesn't share.
Pan Am has Laura who starts out as the very definition of the trope but has slowly been getting some Character Development that might be taking her beyond it.
Musical Theater
In Sweeney Todd: The Demon Barber of Fleet Street, both Anthony and Johanna are often cast as blonds. Johanna kind of requires this though, since song lyrics explicitly state she has yellow hair.
Fantine in Les Misérables often wears a blonde wig to match with her novel counterpart.
Myths & Religion
Thor's wife, Sif, had golden hair. Indeed, after Loki mischievously cut it off, she had literal golden hair, made by the dwarfs. Of course, she was wasn't so much pure and innocent as badass.
Helen of Troy, the most beautiful woman in the world. In the 2005 film Troy, she is played by the blond and blue-eyed Diane Kruger, who is a former model.
In some versions of the myth, Helen was described as blond (as was Achilles) because of the connotations of exoticism.
Blond hair is uncommon in Mediterranean societies even today, so it is frequently seen as a mark of beauty in Greek and Roman myths.
Aphrodite/Venus is also frequently depicted with blond hair.
Final Fantasy XII has both Vaan and Penelo. Balthier, Ashe and Basch are blonde as well but Ashe is a bit of a bitch, Balthier is very mischievous and Basch is The Stoic.
Although several Soul Calibur characters have blonde hair, Siegfried, Sophitia and, to a lesser extent, Cassandra (who is more of a Dumb Blonde) fit this trope perfectly.
Paz in Metal Gear Solid: Peace Walker fits this trope perfectly until she reveals her true personality. It's particularly strange, since she's supposed to be Costa Rican and even has a line in her diary which implies she's not a white Anglo-Saxon, suggesting the blond hair, pale skin and blue eyes is for the audience's benefit.
Annie, Ashley, and Sidney from Backyard Sports fit this trope. Reese and Gretchen are blonde, but don't fit this trope.
Beautiful, young, good, and innocent? That's Amano's concept of Terra/Tina from Final Fantasy VI all over, and applies to a lesser extent to Celes as well. And Relm (she really is a sweet girl, deep down. ...Really really deep down). Next tier has the heroic male characters Edgar, Sabin/Mash, and Locke, who was originally conceptualized with blond hair. If you really wanted, you could argue that General Leo fits this, though he really shines as a subvertedBlond Guys Are Evil, foiling the blond Kefka. The world of Final Fantasy VI has no Canon Name, but we have reason to believe it's Blondania.
Lucas from Mother 3 has gold hair, an innocent personality, he's pure minded, and unlike, Claus, stays good. Claus's hair, orange, could possibly be that way because of red (evil) mixing with blonde (purity)
Wendy from Rule of Rose could have her picture describing this trope; a quiet, sickly little girl with a pretty smile and a blue sundress. Unfortunately also a manipulative Yandere.
Spiritia Rosenberg from Rosenkreuzstilette has flowing gold hair held in a huge ponytail and is a straightforward, honest, and kind girl whose moral convictions are second to none and who is greatly respected by others, including other soldiers of the Holy Empire. Iris also has gold hair, but unlike Tia, believe it or not, she's a Complete Monster who only pretends to be kind and innocent to disguise her true, evil intentions. Both characters are reincarnations of the legendary Magus Rosenkreuz, whom the organization of RKS is named after - Tia got his soul and his ability to tap into the strength of others', and Iris was blessed with his magical prowess and the abundance of knowledge he had acquired over the course of his life.
Sweet, goofy, virginal woobie Alistair of Dragon Age is a strawberry-blond male example.
Visual Novels
Regina Berry, in Ace Attorney, is so sweet and innocent that she actually doesn't understand the concept of death or the consequences of her naive but dangerous actions.
Colias Palaeno has a near-constant smile and is ridiculously friendly to everyone he meets. Which is why Manny Coachen was able to manipulate him so easily.
Also Giada in the B-Side Comic, "Get Your Boyfriend Back".
Agatha Clay, Girl Genius. (Her hair does seem to be turning more strawberry blonde as time goes by, but the trope still holds.) Of course, she inherited the color from her mother, who is a questionable sort, to say the least...
And Zola, who pretends to be sweet and innocent, has even paler blonde hair. But she's evil.
Elan in The Order of the Stick is apparently extremely attractive, in part due to this trope, although it's hard to tell from the stick-figure art. He also fits it very well in terms of personality, being the sweetest and most innocent major character in the comic (as well as not too bright aside from his Genre Savvy).
Apollo, Artemis, Aglaea, and Eros in Thalia's Musings. Apollo, though hardly a Chaste Hero, is one of the more moral gods in the Pantheon and renowned as a champion of moderate living. His twin sister Artemis is a sworn virgin. Both have healing powers as does Aglaea, Apollo's granddaughter, who is a dedicated physician. Eros can make life difficult for his "victims", but he ultimately just wants everyone to find true love, something his parents never had.
Finn from Adventure Time doesn't normally show his hair beneath his Nice Hat, but on occasion he has been known to show off his rather beautiful golden hair which ends up a plot element in an episode, for the most part it's kept compressed beneath his hat with occasional peaks at it.
