In color theory, blue is primarily associated with calmness, peace, and serenity. It reminds us of the open sky and waters, which in turn bring to mind steadiness and restfulness.
A story can utilize this association in many ways. A character or group associated with peace may wear blue to represent their ideals or the group's Mellow Fellow is strongly associated with the color. A quiet scene can be lit with the color blue or a place intended to be relaxing can prominently feature the color. Another common way is to pair this trope with Water Is Blue, since water has similar associations with calmness and serenity — someone associated with water thus has a calm personality.
Compare Heavenly Blue, which pairs the divine with the color blue, and True Blue Femininity, where women (who were historically expected to be cool-headed and down-to-earth compared to men) wear blue. Also compare Blue Means Cold, which has a similar connotation since the cold itself is associated with calm, silence, and loneliness. Tropes like Icy Blue Eyes may fall into both. See also Blue Tropes. When blue represents melancholy/sadness in addition to calmness, see Color-Coded Emotions.
Contrast Red Is Violent and Vibrant Orange. This trope is a big reason Red Oni, Blue Oni is named so; a calm/stoic blue character might be paired with an energetic warm-colored character: for example, the Hot-Blooded hero and the cool-headed lancer.
- Ao Manaka in Asteroid in Love is designed upon a blue Color Motif—her name means "blue" to begin with—and true to this trope, she is quiet, demure, level-headed, and intelligent, in contrast with her Best Friend Mira.
- Oskar von Reuenthal is associated with the color blue in the OVA version of Legend of Galactic Heroes. He is less likely to jump into a scrap than his best friend, Wolfgang Mittermeyer (who is associated with Red). Reuenthal is, however, more likely to kill you once you get him mad.
- When a strip in the art edutainment manga GA: Geijutsuka Art Design Class discusses the colour blue, Namiko complained she has been tired lately, probably due to the stress of being the Only Sane Man of the cast. Ms. Exposition Miyabi suggests the colour blue is effective in cases like that. In the next frame, we see Namiko sitting under a blue sky, and certainly, she is able to calm down and relax with the colour. Sadly the moment is killed by Tomokane and Nodamiki squeeing at the blue sea.
- Magia Azul in Gushing over Magical Girls zigzags this trope. She is the most stoic and composed member of Tres Magia although her innermost desires don't reflect this at all.
- Diana Cavendish from Little Witch Academia is The Stoic who is very aloof, calm and rational compared to the rest of her peers. Fittingly, she is also frequently associated with the color blue, as she has Icy Blue Eyes and much of her attire is colored blue, including the ribbon on her school uniform.
- Hiyori in Slow Loop exploits this trope. She is fond of the ocean for its cathartic properties, being fond of visiting the breakwater and gazing upon the horizon whenever she becomes nervous or stressed.
- The Yuri Genre manga Who Decided That Blues Had To Be Cool!? stars a closeted Otaku schoolgirl Azusa who becomes Pure Azurite — a Magical Girl of the "blue" archetype, i.e. an aloof and stoic close-range fighter. While Azusa is exceptionally good at projecting just that image when transformed, her muggle personality is, on the contrary, vain, fussy, and obsessive, with the gap between the two causing her considerable anguish (though it's mostly Played for Laughs) — especially since she was really hoping to be cast as the personable "pink" archetype.
- BoBoiBoy: The titular hero's water elemental wears bright blue, and is the most laid-back and relaxed elemental. In both the original and Galaxy series, BoBoiBoy Water is summoned by the hero achieving inner peace. However, in the original series, he was calm to a fault, and his laziness constantly got in the way. His Galaxy version seems to have outgrown this, and is now one of the most mature elementals while still retaining his relaxed attitude.
- Divergent: The Erudite faction is associated with the colour blue and each member must wear at least one article of blue clothing per day, as it is a "calming color that helps stimulate the brain".
- The Wish List: When Meg first wakes up in the afterlife, she initially thinks she might be in a hospital because of all the blue, since hospitals use it for a calming effect.
Her initial impression was blue. A lot of blue. Still, don't panic. You get blue in hospitals. A soothing colour.
- In one Hi-5 song, the singer links colours to emotions. She links blue with serenity.
- In a Happy Days episode, Fonzie was having difficulty controlling his temper. He gotten a promotion at work that took him out of the mechanic's role he had been in, where he worked out a lot of his frustrations with hammering, turning wrenches, etc. The new job meant he couldn't do that, so he began fighting more because his temper was so short. Richie figured out what was going on, and had him take up the hobby of building birdhouses, where the hammering and pounding could relieve his stress. Fonzie became more relaxed, giving his leather jacket to Joanie and wearing a blue t-shirt instead of his usual white one.
Richie: Hey, a blue t-shirt?Fonzie: Yeah! A nice, calm blue.
- In The X-Files episode "Pusher", Pusher was arrested and put in a police car. He says that the uniform is a nice shade of blue, a type of sky blue, eventually calling it cerulean blue - then saying that it's a gentle breeze. This was used to hypnotize the driver of the police car and prevent him from seeing an incoming truck of the same color.
- "Blue Skies" by Irving Berlin (Covered Up by Bing Crosby, Willie Nelson and others) extols blue skies and bluebirds as signs that things are looking up.
- In David Bowie's song "Sound and Vision" (from Low) "blue, blue, electric blue" is the color of the room Bowie goes to escape his anxiety and work out his writer's block.
- BIONICLE: The Ga-Matoran, being associated with the element of water, were colored various shades of blue and were always portrayed as the calmer, more level-headed inhabitants of the Matoran Universe, in direct contrast to the red-colored Ta-Matoran, who were were associated with fire and often portrayed as brash and quick-to-anger.
- Animal Restaurant: In "Hamster's Diary 3", the hamster wishes to knit a scarf for Tate, and considers making it in blue, as "it's a gentle and quiet color, and it seems like it would fit Tate very well."
- Bug Fables: Leif is an ice magic-wielding moth with a very calm, composed and stoic personality, almost always speaking in monotone and very rarely displaying any strong emotion. Fittingly, the primary color of his body and wings is blue, reflecting his ice powers and cool personality.
- Dragon Age II: Bethany, the protagonist's younger sister, is the blue oni of the Red Oni, Blue Oni pairing with her twin brother Carver. She has a bright blue background in her icon, and depending on her ultimate fate in the game, may be seen in later acts wearing a blue mage robe. She has easily the calmest and gentlest personality of any character in the game, and is one of the only members of Hawke's group who is universally liked by all the others.
- Enchanted Arms: Toya wears blue, uses water magic, and is calm, composed, and intellectual. For bonus points, he contrasts against Atsuma, a passionate, red-clad fire-user.
- Freedom Planet: The Royal Magister of Shang Tu is a Reasonable Authority Figure with stoic, composed and rational personality, never allowing his emotions to cloud his judgment. Fittingly, his attire is clad primarily in blue colors. This also serves as a contrast to other leaders of Avalice's kingdoms, as Mayor Zao, who wears red, is driven by greed and has temper as short as his height, and Prince Dail, who wears green, is a vengeance-driven Knight Templar (though that's because he was brainwashed by Lord Brevon; otherwise, he's also fairly rational).
- Mass Effect: Blue is the color of the Paragon dialog choices, which involve diplomacy, cooperation, and appeals to nonviolence. This contrasts with Renegade choices, which are red.
- In Mega Man Battle Network, the titular MegaMan.EXE is far calmer and more responsible than his operator, Lan Hikari, who is Brilliant, but Lazy. Whereas Lan daydreams about food and rushes off to be the best NetBattler he can be, Mega Man regularly reminds him to do his homework, often quipping at his expense.
- Onmyōji: Abe no Seimei's default attire is mostly light blue, reflecting his calm and stoic personality.
- Pokémon GO: Team Mystic's Color Motif is blue, and they're associated with calm, analysis, and rationality. Their leader Blanche, who wears blue, is much more aloof and stoic than the peppier Candela (of the red-associated Team Valor) and Spark (of the yellow-associated Team Instinct).
- Sig from Puyo Puyo has blue hair and is often seen wearing prominently blue clothing. He's far more calm and stoic compared to his fellow classmates Amitie and Raffina.
- Samurai Shodown: There are a couple of examples of Sibling Yin-Yang and Red Oni, Blue Oni where one of the brothers is The Stoic with blue as his main color:
- Since the fourth game, Sogetsu Kazama, the Aloof Big Brother of the Hot-Blooded Kazuki Kazama, has had blue as his main color (with blue hair and light blue outfit) and managing water powers, contrasting his literal "hot" brother.
- Warriors Rage shows the Hero Protagonist Seishiro Kuki as a calm and aloof character, with the blue as his main color antagonizing with his evil adoptive young brother Tohma Kuki, who dresses in red and orange.
- Sleepless Domain: Undine Wells is strongly associated with the color blue, as seen throughout her costume, hair, and speech bubbles. She is also the most reasonable and least assertive member of Team Alchemical, and often ends up in the role of a mediator between her friends. Fittingly enough, her power as a Magical Girl is to control water.
- Double Subverted in Villain to Kill. Cassian is even more irritable following his death due to his grudge against Lampas for killing him and tarnishing his name on false charges. His confusion and rage results him in activating Gangu's villainous powers, which are colored blue and black instead of bright red like his old "Ignition". The Moros informs Cassian that he runs the risk of becoming a bloodthirsty lunatic if he doesn't get a handle on his emotions from now on, forcing Cassian to do a better job of keeping his cool.
- Ask The Story Bots: Bang is a very relaxed and laid-back StoryBot that happens to be blue.
- Ready Jet Go!:
- Jet and his parents all wear blue. While they are usually peppy and cheerful, they are rarely angry and stay calm when others get frustrated. The one exception to this was when Zerk provoked Jet in "Whole Lotta Shakin'".
- Dr. Skelley's entire outfit is varying shades of blue, and she is the calmest and most level-headed of the DSA scientists (Bergs is a coffee addict, Rafferty is a worrier, and Mr. Peterson is....Mr. Peterson).
- Steven Universe:
- Sapphire, a blue-colored Gem, provides Garnet with her calmer side, as opposed to Sapphire's hot-headed fusion (and romantic) partner Ruby. When she gets into an argument with Ruby, Ruby has frequent angry outbursts, but Sapphire literally freezes up and isolates herself, avoiding conflict until she apologizes to Ruby.
- Blue Diamond is the most mellow of the Diamond Authority, especially compared to Yellow's authoritarian temper, Pink's immaturity, and White's tendency towards mind control. She has a very deep and soothing voice, and while she is the only one of the Diamonds to openly mourn Pink, her crying is very subdued (though she does project her feelings to other gems around her). After Era 3, her calm nature is even more present, as she uses her powers to share happiness and soothe other Gems.