Raven: [disgusted] Don't smell it? I can see it!
Cyborg: [horrified] It's thick enough to cut through! [snips off a piece of the stench, which falls on the floor]
Viewers of fictionland can only experience things through two senses: sight and sound. So what do you do when you want to make it clear that something smells? Make the smell visible!
Smells are even colour coded. Bad smells are usually green, yellow, or brown, and are sometimes accompanied by flies, while nice smells are usually pink, blue, or possibly brown if the scent is coming from food. Burnt smells are given a charcoal grey colour, while coffee is given a trail of steam. Whatever the colour, the smell is usually depicted either as a trail of vapour or as little wiggly lines or "waftarons".
The Rule of Perception is the whole reason for this trope's existence. If the audience isn't aware of something, it doesn't exist. Therefore in order for a smell to exist, it has to be able to be seen or heard by the audience. Creators use this trope as a non-intrusive way of informing the viewers, as it doesn't interrupt flow of the scene like having characters break off from a conversation to comment on it would.
Used in animation much more often than it is used in other media, as in Real Life this usually doesn't happen, and would disrupt the immersion of the audience if it was used in, say, a Live-Action Film. In other media, viewers are more likely to be informed of the smell by people complaining about it. It is worth mentioning that there are plenty of chemicals that do have distinctive aromas that also give off visible fumes, but in most cases, the two are independent of each other and can occur together or on their own.
This is a Sub-Trope of Editorial Synaesthesia. May be caused by a Smelly Skunk, a Weaponized Stench, Wilting Odor or Toilet Humour. Compare Tastes Like Purple. Follow Your Nose is when an enticing smell is not only visible but strong enough to carry a character along. See also Technicolor Wind when the air itself is color-coded.
- In a commercial for Energizer batteries, these kind of odors show up in a commercial for Airdale air freshener, the fictional product being advertised. Not only are the stink lines visible, but so are the letters spelling out the different types of odors. They disappear when the lady advertising Airdale uses it in her kitchen, on her pet dog, and on her husband's smelly feet.
- A Guinness advert shows the two animated brewmasters attending a tailgate party outside a football stadium. The younger brewmaster points out that it's a local custom to wear cheese on your head (a reference to Green Bay Packer fans), so he brings hunks of limburger for them to wear. The cheese gives off a greenish-yellow aura as the stench drives away the other tailgaters.
Older brewmaster: I'm not so sure we're fittin' in.
Younger brewmaster: I smell feet.
- In the "Dancer" commercial for Kellogg's Pop-Tarts, the pastries in the toaster give off a visible vapour. Ten percent of the vapour is strawberries, representing the ten percent fruit in the filling.
- The Poo~Pourri adverts represent the smell of the poo with brown skulls and spirals, and the nice smell of the Poo~Pourri with leaves and flowers.
- BoBoiBoy Galaxy: Green odors indicate stench, as seen in "Katakululu's Hypnosis"; where a pile of alien food which includes carcasses is visibly putrid to imply rotting flesh, as well as in "Emotion Manipulation"; when Fang gets inflicted to puke every so often, and each time he retreats to the restroom, a green smell comes from behind the restroom door.
- Bread Barbershop: Cheese has a sickly yellow aura representing his smell.
- Noonbory and the Super 7: In "Rosygury and the BeeBee Trap", Rosygury's perfume is visible via a pale pink mist.
- Jet and the Pet Rangers: Green odors are particularly prevalent in the first episode since it's about a cat who won't take a bath and manifests a monster out of his own fear and odors as a result.
- Pleasant Goat and Big Big Wolf: In episode 173, the wolves notice a nice smell coming from the goats. The smell is visible as a trail of white steam.
- One arc in Mononoke depicted smell with colours, whereas almost everything else was Deliberately Monochrome.
- In One Piece, Usopp's Egg Star involves him firing rotten eggs from his slingshot and releases a green vapour.
- The character Honey in Ouran High School Host Club always has floating flowers around him.
- In Episode 3 of Star★Twinkle Pretty Cure, some donuts produce a white mist, which leads Prunce to them.
- In Asterix and the Soothsayer, when Getafix brews a cauldron of liquid with a nauseating smell in order to convince the Romans that the fake soothsayer's prophecies are real, its malodorous aroma is represented as a kind of pale bluish-grey. He later brews another cauldron of liquid to explain what Cacofonix seen and that the soothsayer is a fake.
- In the film version of Anonymous Rex, scents carried by particular dinosaurs were conveyed vivid visual depictions of the scent items. For example, one dinosaur smells of peaches and cream and, images of brightly lit peach slices falling into cream appear on the screen.
- Daredevil. The title character experiences his Disability Superpower as a 3D 'radar' effect, and this trope is shown whenever he's concentrating on scent instead of sound.
- Averted by Polyester, in which audience members were given "Smell-O-Rama" scratch and sniff cards.
- In Children Of God, an alien who has a far better sense of smell than a human is tracking a missing friend. She "sees" his scent as points of light along the trail.
- Captain Angua, a member of the Ankh-Morpork City Watch and their token werewolf, is described as perceiving the world primarily through scent rather than sight while in wolf form. The text describes it in terms of ribbons and clouds of brilliant colors, far more vivid than anything she's able to actually see as a human. She's even able to track criminals by their Fluorescent Footprints.
- Granny Weatherwax experiences the sensations of animals she's Borrowed in a similar way.
- Stephen King's novel The Eyes of The Dragon has a passage written from a dog's point of view, in which scents are described as lines of various colours.
- Peek A Boo Poo: When Alfie poops in a pan and in a pot, stink lines are seen.
- In The Pigeon Needs a Bath, one of the ways you can tell is the visible stink lines depicted on him on the pages where he insists he doesn't have a smell.
Pigeon: What smell? [sniffing himself] I don't smell anything! And if I do — it's very normal smell. For a pigeon.
- Scents are described in a similar way for Wolpertings in Rumo & His Miraculous Adventures.
- CSI has Bloodhound-O-Vision, which displays the visible world in black and white, while scents appear as colourful patches.
- Daredevil: Matt Murdock is blind as the result of a childhood accident, but his other senses are greatly heightened, to the point where he describes to Claire Temple that the combination of smell, sound, and air vibrations are akin to "seeing" a world on fire, per the title of that episode.
- The Binding of Isaac: The many Fartillery attacks used by enemies and by Isaac are usually coloured green or brown. A couple of items give you farts that can charm enemies and these are pink instead, which possibly indicates that they smell nice. There's also the Dead Tooth item that gives Isaac poisonous halitosis, which is represented by a green cloud around his face.
- In Boogerman, the eponymous protagonist uses Fartillery as his main weapon; his farts are visible with a green colour.
- The Praetorians and Glpyhid Oppressors in Deep Rock Galactic release obnoxious green gas upon being killed which the dwarves call it "death farts". The ice version of Praetorians release freezing gas and the radioactive version leave behind a radioactive field upon dying.
- In Discworld Noir, while playing as a werewolf you can indeed see scents as patches of coloured mist. They can be 'collected' like items and you have to match the patterns to ones you've encountered before to track where characters have been.
- In Dog's Life, Jake can sniff out smells. Each smell has its own colour.
- In Far Cry Instincts smell is shown as a coloured aura and trail.
- In Fizzball hitting a skunk before the Fizzball is large enough to contain it or destroying a toxic waste barrel by hitting it too many times produces a green cloud.
- Sveta's Track Psynergy in Golden Sun: Dark Dawn allows her to find scent trails, which appear as a streak of white vapour close to the ground.
- The Legend of Zelda:
- In Leisure Suit Larry 7: Love for Sail! Larry still yellow fumes when he farts. The game also comes with Scratch and Sniff cards, allowing the player to actually smell what is happening.
- Plants vs. Zombies:
- Garlic emits a grey-green gas from its top, and has the effect of repelling zombies into an adjacent lane to the one it is planted in.
- In the sequel, Chili Bean has the effect of making the zombie that eats it fart, which stuns all the zombies behind it. This is represented by a green cloud appearing behind the zombie.
- Stunion can stun zombies with its bad breath, which is also represented as a green cloud.
- Perfume-shroom has the effect of temporarily making dinosaurs friendly, and its scent is represented as a pink mist that emits tiny hearts.
- In Pokémon Mystery Dungeon: Explorers, Skuntank and Koffing's stink is portrayed visually as a purple cloud.
- Saints Row: The Third: Upgrading the Flashbang grenade to level 4 turns it into the Fart In A Jar, which when thrown releases a cloud of brown gas that causes everyone caught within it to start vomiting from the stench.
- In Samurai Shodown Earthquake in the first 2 games farts on the enemy, shown as a purple cloud.
- In Level 2 of Sheep, Dog 'n' Wolf, Ralph uses a bottle of Lady Sheep — the perfume for lady sheep that no male sheep can resist™ — by the means of using a fan to propel its pink cloud of odor in order to entice a sheep.
- The Sims:
- In South Park: The Stick of Truth, the fart icon is a green cloud, although your actual farts have no colour. Additionally, people inflicted with the Gross Out effect (similar to poison) and people you have farted on outside of battle will be surrounded by green mist.
- Super Paper Mario:
- Averted when Merlee has a fly buzzing around her after hiding in a toilet, indicating that she smelled, this was not visible in any other way. This was probably to make it harder for the player to tell her apart from the shapeshifter Mimi.
- However, this is played straight with O'Chunks, whose farts are yellow-green.
- The Fart in a Jar accessory is a bottle filled with light green gas. It gives the player the ability to fart in order to double jump and surrounds them with green clouds when it is used. Upgrading the jar further to a Fart in a Balloon colours the entire balloon green.
- The Stink potion can be thrown at enemies and other players to give them the Stinky debuff. The only effect this has is to make them emit green fumes for 30 seconds.
- Homestar Runner: In the Strong Bad Email "the chair", Strong Bad takes a good look at his ratty old stool and sees clouds of smell in the shape of the word "STANK" coming off it.
Strong Bad: Woah, it's been upgraded to "stank". Eeew... Maybe it is time for a re-imagining of my email-checkin' chair.
- In the official Team Fortress 2 machinima "Expiration Date", several of the unflattering pictures that Scout draws of Spy (under the guise of submitting everyone's dying wishes for Spy to read out) incorporate these. One supposedly depicts the Eiffel Tower emanating a smell, as a jab at Spy's nationality.
Spy: Our first dying wish is Scout's. He's... drawn a picture of me getting hit by a car. I have something radiating off of me.
Scout: Yeah, those are stink lines. That's why the car hit him. 'Cause he smells.
Spy: [unamused] Yes, I see.
- Dean & Nala + Vinny: Dean has to air out his van after leaving some prawns in his mini fridge and forgetting about them. The stench is portrayed as greenish clouds in a black-and-white strip. Nala and Vinny (cat and roach) have different reactions to the smell:
Nala: Mmm! What is that bewitching aroma?
Vinny (in a gas mask): Don't buy a gas mask, they said. Waste of money, they said.
- In 8-Bit Theater, Black Mage says that Elfland stinks of elf, which is accompanied by a picture of an elf emitting green stink lines.
- Arthur's Perfect Christmas: To show his family's tradition of Sankta Lucia, George brings a tin of dried and boiled Swedish fish called lutefisk to class and offers it to his friends. It has a definitely visible odor and naturally everyone passes it around as rapidly as they can, except for Buster, who tosses a piece into his mouth, says "Yum! Not bad," and goes for another while George watches happily.
- Avatar: The Last Airbender: The vision of an animal that uses its sense of smell to "see" is represented in streams of different colours, each representing a different scent.
- Camp Lazlo: Other campers were unwilling to take a bath after getting extremely dirty. So they hide from Lazlo behind a bush. Unfortunately for them, Lazlo saw their stink lines above the bush.
- Classic Disney Shorts: In "R'coonDawg", Pluto's ability to track down prey is shown by having whatever he was smelling appear before him, with the narrator explaining that it was as if he could see with his nose. The raccoon he's chasing exploits this by using a fish, a frog, and a horseshoe to lose his scent, causing Pluto to see bizarre raccoon/fish/frog/horse hybrids.
- The Crumpets uses yellow-green clouds for bad smells, like from Granny's onion crisps, the bath-avoiding King in "Amnesia", and the stench inside the van in "Road Stories".
- Doc McStuffins: In "Brontosaurus Breath", Bronty's bad breath due to a bit of salami stuck in his teeth is represented as a sickly green odor.
- Esme & Roy:
- "Monster Trucks": Tillie gets one after getting very dirty and needing a bath.
Roy: Monster Fact 5976: When Plink monsters get dirty, they get really stinky, like majorly monster stinky.
- "Supermarket Match": The "scratch and stink" stickers that Tillie gets for winning the game of Supermarket Match have this to show their stinky odor.
- "Monster Trucks": Tillie gets one after getting very dirty and needing a bath.
- Whenever a character is said to have bad breath, green lines emanate from their mouth.
- "Let's Play Ecologists": Kaeloo gives Stumpy a piece of stinky cheese to throw away that has squiggly lines over it to represent its odor.
- Kate & Mim-Mim: In "Bathtime for Boomer", Boomer badly needs a bath, as clearly indicated by the green stink lines coming off of him, though these aren't shown after around the beginning of the episode, apparently given that we're supposed to take it for granted that he's still stinky.
- Looney Tunes and Merrie Melodies:
- Scents are often depicted as a ribbon that snakes through the air toward a character, and can even lift the character into the air and carry them toward the source of the smell.
- Other times, they're depicted as a coloured aura or mist instead. Notably, Pepe Le Pew's body odour is a murky green fog, which other characters only smell by visibly inhaling it. Similarly, perfumes are pink and food is blue-grey.
- The Magic School Bus: Justified in "The Magic School Bus Makes a Stink". When Ms. Frizzle is teaching her class all about smells and how they work, she offers them Smell-a-visors that make odor molecules visible, and color-coded depending on the source of the smell, like red for roses or off-white for gym socks.
- My Friends Tigger & Pooh:
- "Beaver Gets Skunked": Skunk's stinky spray that upsets Beaver so much is depicted as a noxious cloud of green odor.
- "Skunks Non-scents": All of the stinky scents that the Super Sleuths try out for Skunk, as well as the stench that Skunk is eventually able to make are depicted as stinky green odors.
- My Little Pony: Friendship Is Magic:
- "Dragonshy": The dragon's smelly breath is green.
- "Winter Wrap Up": Twilight is sprayed by skunks after being chased by bees into the burrow they were hibernating in. The skunks leave a trail of green mist behind them, and in the next scene, Twilight is also surrounded by a green cloud.
- "Baby Cakes": Pound Cake and Pumpkin Cake's dirty nappies emit a green vapour.
- "The Parent Map": While acting out a friendship problem, one of the booksellers states that she doesn't wish to cover up her "natural scent" with the essences, and illustrates her point by lifting her foreleg, giving off a visible odor from her armpit.
- "The End in Friend": The bufogren's halitosis is visible as a cloud of green gas coming out of its mouth.
- Phineas and Ferb:
- "Misperceived Monotreme": Lampshaded when Major Monogram sees Carl the intern eating a peanut butter, banana, and sardine sandwich (complete with stink lines), and claims "I can see the smell from here!"
- "Lights, Candace, Action!": Lampshaded with Doofenshmirtz's aged cheese that is so stinky that he proclaims "you can actually see the pungent aroma."
- The Powerpuff Girls (1998): In "Reeking Havoc", the giant fart monster is a sentient brown cloud created from the collective farts of everyone who tried Professor Utonium's Chemical X-laced chili. Blossom defeats it with a giant lit match.
- SpongeBob SquarePants:
- The scent of cooking Krabby Patties are given a smoky white.
- Rancid smells, like the time SpongeBob ate a "sundae", are given a rancid green colour that emanates through the air around Bikini Bottom.
- Then there's the Perfume Department, where the chokingly fragrant smells are pink and light blue.
- "Born Again Krabs": Lampshaded when SpongeBob presents Squidward the rotten patty Mr. Krabs is forcing him to serve, he asks if he could get one with less fog.
- Star Trek: Lower Decks: In "Moist Vessel", the foul stench from the holodeck filters is illustrated as green vapor.
- Teen Titans Go!: Beast Boy's disgusting odor is visible as a green fog around him in "Hot Garbage". When he says he doesn't smell it, Raven incredulously responds that she can see it, while Cyborg adds that it's thick enough for him to literally cut a wisp off of.
- Tinga Tinga Tales: Skunk initially produced a nice smell, represented by pink. However, Baboon tricked him into eating a Smelly Fruit, which made him produce nasty smells instead. These were represented by green.
- ToddWorld: In "Todd Builds a Fort," Benny digs up a buried cream doodle from 1969 which he says is "still fresh." Todd grabs and throws it away, saying that it isn't, and one of the ways you can tell is that it has visible stink lines emanating from it. The same is true in "Pickle's Smelly Socks" in which Pickle has a problem with terrible sock odor, but nobody wants to tell him.
- Total Drama Island: In "Hide and Be Sneaky", the campers must hide from Chef Hatchet, who is hunting them down with a water gun, and make it to a safe spot to earn immunity. Bridgette accidentally startles a family of Smelly Skunks, resulting in her getting sprayed and discovered by Chef after she screams in horror. Bridgette begs Chef to spray her with his water gun to wash the stench off; just as she thought the stench wore off after being soaked, the stench quickly returns and lingers on Bridgette for the remainder of the episode.
- The Transformers: In "Starscream's Ghost", a visible stench from alien food wafts towards Octane's nose and he audibly sniffs it.
- Work It Out Wombats!: There is a visibly green stink coming from Snout in "Snout Wash Day."