Blue with Shock

If something truly traumatic occurs to an anime character, or they are mortified or embarrassed beyond all reckoning, the upper half of their face, or even all of it, may turn blue—at least until they recover.

A variation on the effect takes the form of a set of wavy blue lines that radiate upward from the character's head and shoulders in a manner reminiscent of a Battle Aura. Darker-blue lines streaming down their eyes like very straight tears optional.

It's usually used for comedic effect, and not in actually serious situations.

The implication is that one is so surprised that you can't breathe, and therefore, subsequently turn blue from lack of oxygen. The lines, when present, are a reference to horror manga art styles.

Along with Sweat Drops and Cross-Popping Veins, this visual shorthand is starting to creep into Western animation, be it Animesque or not (as testified to by the page image).

Can be combined with Blank White Eyes for extra impact. Compare Color Failure.

Anime and Manga

 * Merrill in Rune Soldier Louie undergoes this several times. Melissa in the same show suffers the wavy blue line variant at least once.
 * Excel in Excel Saga demonstrates the full-face version at least once.
 * It's found several times in the last few seasons of Ranma ½, although almost not at all in its first half.
 * Roy Mustang in Fullmetal Alchemist admonishes his aide Hawkeye for pulling him away from a fight. She calmly explains that he would certainly have been killed, his alchemic powers don't work in the rain, and he failed to notice it was raining. Mustang gets the blue face and Blank White Eyes.
 * Al's version of shock can vary from just his head to most of his body. Keep in mind that he's an empty suit of armor with the soul of a sensitive ten year-old.
 * After the Orange Islands arc, Brock from the Pokémon anime would curl up into a ball and radiate Blue with Shock several feet away whenever Professor Ivy was mentioned.
 * In the first episode where Brock does this, Ash does it as well at the mention of his rival Gary (no doubt to many slash fanficcers' delight).
 * Pikachu. Note that during this, Swellow turns green, Torkoal purple, Ludicolo orange and Grovyle turns black and white. All the color of the shocked rainbow, as it were.
 * ...What the heck caused that?
 * Lethal Chef strikes again.
 * Occurs constantly in Naruto, much like the Blank White Eyes.
 * Azumanga Daioh also uses this several times, mostly when Sakaki's having a mental image of something impossibly cute. Anyone riding in the Yukari-mobile (such as poor Chiyo-Chan) tends to turn white instead.
 * Yukari herself did the white with shock variant in the very first episode. Considering the things she said before it was pointed out she was in the wrong classroom, it's entirely understandable. If Azumanga Daioh was live action, she still would have gone white with shock.
 * Osaka combines this with Blank White Eyes when Tomo starts pestering her on her first day.
 * Kagami and Konata in Lucky Star delight in squicking the hell out of each other, to this effect.
 * Tell us Hiyori, exactly what is yaoi?
 * In Clannad, Kotomi and Tomoya go blue with shock after receiving a bad fortune. Nagisa and her mother also do this separately in theatrical fashion, with identical lightning strikes in the background.
 * Many situations in Cromartie High School conclude with this, with one or more of the main characters expressing distress over the punchline of the situation at hand. The situations are beyond explanation, because, well, it's Cromartie High.
 * One episode of Rozen Maiden when Shinku doesn't wake up, Suiseiseki tries to see if hurting Jun will wake her up. By holding a huge knife over his head with Jun lying on the floor. The knife drops, embedding into the floor, an inch from his face. Cue Blue with Shock Jun.
 * Ahiru from Princess Tutu pulls this off a few times, and once as a duck when she realises that Fakir (who looks like he kicks puppies as a favourite pastime) just found her hiding place.
 * Tsuna from Katekyo Hitman Reborn does this quite often, especially when his Unwanted Harem does something not so normal...
 * D.Gray-man has its moments when Allen realizes that the load of empty wine bottles Devit and Jasdero show to him are the ones that Cross had made Allen buy for him when he was still training... well...not so great results...
 * Funny thing is that he wears this face for about ten minutes.
 * Everyone does this constantly in Sayonara, Zetsubou-sensei, complete with black lines going down the whole face.
 * Happens to the most unlikely of characters in Hayate the Combat Butler. In one episode (25, I think), even happens to Number 8, who is a Ridiculously Human Robot.
 * Rurouni Kenshin did the "emanating waves of depression" version when he remembered the kind of training his Sink or Swim Mentor put him through.
 * In Soul Eater, Death The Kid usually has this look when he sees or thinks something is out of symmetry. Liz whenever ghosts are around.
 * Germany in Axis Powers Hetalia has many moments like this, complete with black lines, whenever he is surprised. He also emanates blue lines after Italy reveals his fetishes to the allies during questioning.
 * Italy turns Blue with Shock after sampling some of England's food, which goes to show how much of a Lethal Chef England is. He turns blue again in the same episode, after the Allies point a gun at him while trying to get him to spill some secrets.
 * The "dark blue lines like tears" part of this trope occurs often in Ouran High School Host Club like in episode 9 for example.
 * FLCL
 * Episode 1. After Haruko runs into Naota he's knocked unconscious and his forehead turns blue.
 * Kitsurubami, after she unconsciously takes a sip from Amarao's exercise bottle.
 * It's almost a once-a-page occurrence in Beelzebub, especially when Furuichi is around.
 * THE iDOLM@STER - Yukiho had several of these at the beggining of the series. Haruka, Makoto and Iori also had one in at least one occasion.
 * Gai Kurasawa of Darker than Black sometimes does this.

Fan Fiction

 * Happens to Minato after a careless comment in this fan fic comic

Music
"Brother's headed that way; now I guess He just read something made his face turn blue Well I got nothing 'gainst the press They wouldn't print it if it wasn't true"
 * "Sunday Papers" from Joe Jackson's first LP Look Sharp!:

"I saw a little kid As he walked around He picked a candy bar up Off the ground He chowed about a half Then his face turned blue Turned out that candy bar was a doggy-doo."
 * Don't Pick It Up by The Offspring:

Video Games

 * Happens many times to Muza in the video game Thousand Arms when he sees a girl. At one point, the hero has to literally drag the frozen Muza around town.
 * In Elite Beat Agents, this happens to Don and Jane when their date gets repeatedly interrupted by hungry/skateboarding/tired meddling kids. Also, this happens to most other characters just before they start arm-waving.
 * Pac-Man is technically an example since the ghosts turn blue whenever he eats an energizer/power pellet. The same principle also applies to the TV show, even though they don't turn blue here (instead, they turn "purple with panic").
 * Levin's "surprised" animation in Soul Nomad and The World Eaters involves this.
 * Mario/Luigi's death animation from Super Mario World.

Western Animation

 * In the The Legend of Korra episode "The Voice in the Night" Tenzin goes blue in the face at a high-society gala when his five-year-old son Meelo uses something as a toilet off-screen.