Olfactory-visual synesthesia

Its subtypes, which can occur separately or together, are smell-colour and smell-shape

This is one of the types of synesthesia that can be called "visualised sensations" or "coloured sensations"

Image: Pau 365. The smell of a flower, 2018.

This is the visual experience of the smell of a flower in Portugal in 2013. I saw the shape projected in the air because I had hyperosmia at the time, giving me an extremely sensitive sense of smell and causing very strong synesthetic experiences. I normally only perceive the shape of smells in my mind’s eye.”

Olfactory-visual synesthesia is not a particularly common type (according to Sean Day's study, around 6% of synesthetes could have it, suggesting that the prevalence of people who “see smells” is similar to that of people who “see tastes”.) It manifests in two main ways: colour and shape, and a synesthete may experience either just one of these or both of them together. Projector synesthetes, who are clearly a minority, see the shapes or colours physically in front of them when they smell something, while associator synesthetes only see them in the mind’s eye.

Photisms created by smell usually have a spatial location; they can be high or low, for example; they can be clearly vertical, horizontal or diagonal; for some people they have movement: they can rotate, sway, oscillate or jump about, repeatedly expand, replicate, or travel constantly in a certain direction. They often have a major emotional component. For some people with this type of synesthesia an additional tactile sensation is evoked (the shapes are felt in a specific part of the body: hands, arms, chest, etc.), although this appears to be rather uncommon, occurring much more frequently with taste synesthesia than with smell synesthesia.

The visual concurrents are consistent but can be more or less pronounced depending on the person’s olfactory capacity at any given time (our sense of smell has “good days” and “bad days”, as it were) and it can also depend on factors such as the degree of focus on the experience, relaxation or stress, emotion and mood. For some, colours and/or shapes are triggered by all smells in general, while for others it is more selective and they are only produced by certain types of smells (see the example below of a person who only has concurrents for people and their clothing), or the smells have to be strong, or new and interesting, for example. (This article on some of the science behind the selective nature of smell and new research in this area is relevant if you want to find out more about this aspect.)

People with olfactory-visual synesthesia very often have gustatory-visual synesthesia too, so their colours and/or shapes are induced by smells and also tastes, and in fact they sometimes confuse them as the experience is so similar.


Smells trigger colours, but they either have no specific shape or the colour experience is much more important than the shape perceptions, which exist but are vague.

Anti-freeze”, by Corinna in the Gallery of the website Sensequence

The smell of anti-freeze for the windscreen-washer. The smell varies briefly between green and pink; if I smell it for a longer period (e.g. in the car), the green and pink streaks mingle like coloured fog.”

“I remember most accurately scents. We were preparing to move into the house I grew up in. I remember at age 2 my father was on a ladder painting the left side of the wall. The paint smelled blue, although he was painting it white. I remember to this day thinking why the paint was white, when it smelled blue.”

(Source: the synesthete MN, quoted in the book Synesthesia: A Union of the Senses by Richard E. Cytowic, 2002, p44.)

The case of a smell-to-colour synesthete perfumer

The perfumer Frédéric Malle created these illustrations for the limited edition release by the perfumery Editions de Parfums at Barneys New York in 2012. He explained in an interview:

“When smelling fragrances I see colors. This capacity to translate scents into images is called synesthesia. A few years ago, I decided to put these visions that I have when smelling the perfumes of our collection on paper. I used Photoshop, its many layers and its many brushes to illustrate the layers and textures that I smell when smelling these scents. At first the purpose of these images was to explain each perfume not using words. While I receive inspiration from all things– nature, things I see while walking, design, I certainly am also inspired by these colors.”

(Source: this article on the website Perfume Polytechnic. 2015.)

This coffee-related website, Perfect Daily Grind, has an article about Victoria, a barista who smells the colours of the different coffee varieties she prepares and paints them.


The shapes perceived in response to smells are geometric figures, simple or complex, or highly idiosyncratic abstract forms, often very complicated and not reminiscent of anything that exists in real life. Some of the most common shapes described are spheres, ovals, lines, curves, blocks or rectangles, spiky shapes, triangles or pyramids, cones or wedges. The shapes can often seem to replicate, repeating themselves, sometimes to infinity. They can have colour and/or texture or they can be colourless and without any texture in particular.

(Image: Cuccoteaser, in Reddit/Synesthesia, 2014. "I attempted to draw a few smells.")

“For smells, it's mostly in terms of their smoothness/spikeyness. Some acrid smells are compact and are kinda covered with spikes (vinegary smells), while others have like a single long spike (ammonia). I have a deodorant that kinda just rolls and bobs around inside my nose, without any spikes at all. Most of the time, it's only vague impressions and more complex smells don't have easily identifiable shapes/motions.”

(Source: This post on Reddit/Synesthesia. 2018.)

"For as long as I can remember, smells have given me a very strong visual, which is always a sort of pattern of black dots. Some smells are dots spaced apart and others are clustered up in sections. Some smells as 2D and others 3D. The picture in my mind is always so strong. I wish I was a better artist, I’ve drawn many scents before but the pictures don’t turn out exactly like what my mind is seeing. (...)

For eg, most food smells are flat, 2D (especially meats) but herbs are usually all 3D with a more dense, flowing pattern."

(Source: These comments on Reddit/Synesthesia. 2022.)

Artist Jingyi Li kept an incredible diary as one of the projects for her fine arts degree in Spain, painting and describing in detail her complex shape/colour/movement perceptions for tastes and smells, along with the emotions they create. 

You can see her series about the scents of different essential oils in the Facebook group I have Synesthesia: I'm not a freak, I'm a Synesthete.

Smell-colour and shape

Smells evoke photisms where the colour and the shape are equally important.

“Basically, for as long as I can remember, when I eat particular food or smell particular scents (so my taste and smell senses), I seem to sense it in shapes and colours.

Like a certain smell I will experience as a soft, blue circle. Or perhaps a soft triangle.

But I don’t actually see any colours or shapes in my vision. I just feel like that’s what it smells or tastes like.

I essentially just “know” that those scents or tastes is a certain shape and colour (and sometimes just one of the two).”

(Source: This post on Reddit/Synesthesia. 2020.)

I've had this all my life, where the way a person or piece of clothing smells has a distinctive color or shape. Like my friend smells like a white rectangle with green splotches behind it on a black background, or my dad smells orange with a black wave around it. (…) It’s only those certain types of scents.”

(Source: This post on Reddit/Synesthesia. 2020.) 

How gustatory-visual and olfactory-visual synesthesia can help you cook

Some synesthetes have this skill or have been able to cultivate it.

"When I eat or drink something, I always visualise the taste as shapes and colours.
When I'm cooking something, I only need to smell the food, and I know exactly how it looks like. Then I search for missing things or mistakes in those visuals and that's how I know what to add."

(Source: This post on Reddit/Synesthesia. 2019.) 

Smell-shape/tactile sensations (possible olfactory-tactile synesthesia)

I haven’t found any cases where someone has an exclusively tactile reaction to smell, as is the case with sounds in auditory-tactile synesthesia, for example, which triggers sensations on the skin and in different parts of the body that are often only tactile and have no visual component at all. However, I was able to chat online with this interesting person who has smell-shape synesthesia and perceives the shapes in a tactile way, so the tactile and the visual coexist, as often occurs with taste-shape synesthesia but apparently much less frequently in the case of smell-induced synesthesia. In his particular case, he perceives the abstract and geometric shapes as within him, near him or actually touching him: they are “felt” rather than “seen”, although they are sufficiently visual for him to be able to draw them.

(Image: Shpongulate, 2019.)

I notice that I experience the shapes of these smells in my upper body, in my arms, and the edges of the shapes are near my hands. Although I've never really thought about it that way! In one sense the shapes are just "in my mind", but spatially they are close to my body, and effectively standing on me.

It's really interesting to compactify these into visual shapes, because they really aren't JUST visual, it's a multisensory experience with it's own flow of energy that defines what it is."

Source (image and text): This post and comments on Reddit/Synesthesia. 2019Read more about this type on the page on olfactory-tactile synesthesia.


Go to the page on olfactory-auditory synesthesia (smell-musical notes or sound)

Go to the page on olfactory-tactile synesthesia

Go to the page on smell and memories (not a type of synesthesia)

Go to the page on gustatory-visual synesthesia (taste-colour/shape)

Go to the page on taste-colour synesthesia

Go to the page on taste-shape synesthesia

Go to the page on gustatory-tactile synesthesia (taste-touch sensations)

This page last updated: 18 June 2024


  1. There is only one sort of scent/smell I can see in my head or in my mind and it's only when I go out of town and lower down my window. And I can smell the scent fresh but sharply that I think I can also maybe taste it but it comes into the center in-between my mouth, my nose and my brain and the shape is a soft shaped really light blue almost white cube that varies in size depending on how much I breath in and focus on the shape and the longest it has lasted was about 10 minutes but it's always only been this one scent/smell in open fields when I go out of town and I can also smell and taste the size of the shape when I focus in on it but I can do it without closing my eyes and I can feel the softness in my nose even tho the scent/smell is fresh and sharp maybe like breathing in fresh oxygen or also like the mickey mouse mask they put on you at the dentist when your a kid.

    1. That's interesting.... maybe you'll discover more if you focus on more smells, if a strong experience gives you this kind of shape/colour then probably for other smells you're experiencing it too, but just very weakly. That was what happened to me. I wonder if the emotion of suddenly being out of town comes into it, that can make for a stronger experience than things that are just there every day. Fresh air is light blue to white for me too! Thanks for posting!

  2. Okay but, whenever I look at someone or something I get a wiff under my nose of what my brains thinks it smells like idk if this is synesthisa but im very confused and it has been happening for around a year and a half now if you have any of advice on what this could be please reply, Thanks :)

    1. If the smell you get when you look at the thing or person is the actual smell they would have in real life, then that wouldn’t be synesthesia but rather something called “olfactorisation”, where the brain can recreate a smell you figure or remember and it does it so well that you actually physically smell it. You could also call it olfactory hyperphantasia, which would be the ability to recreate smells almost at will. A cool ability to have!
      Our sense of smell is better some times than others, it kind of “comes and goes”, which is why these things can happen at a certain time in your life, on some days more than others, during months or even during years, or seem to suddenly start and stop for no particular reason. This might explain why it’s only been happening to you for the last year and a half. Anyway, I think it is something to be enjoyed 😊

  3. There are a few specific insects that I can smell whenever I see one. Each insect has a smell that is unique to that type. For example this one kind of moth has the "moth" smell and I never smell that same scent unless I see that one kind of moth. How can this be explained? Note, these are not insects that emit odors.

    1. This is very interesting, and it's a different type of synesthesia to the one described here: this is concept-smell, when components in a particular series or sequence each trigger their own consistent smell. It's described on this page:
      I'd like to add your example to the page actually, I think it's quite unusual and illustrative. Thank you for describing it!

  4. My whole life, every thing that I smell has a texture. Some smells are flaky, some are smooth, others are sharp points. I wouldn't say that I see geometric shapes - it's more like the edge of a shape that I can feel breaking against my body rather than something that I see.

    1. Wow, I certainly recognise the "edge of a shape" feeling as it's happened to me, although with tastes not smells. Like the shape isn't complete or you only perceive the right angle making one side of a cube or something, I felt that against my hands when I was tasting a wine the other day. I loved the experience of tasting the wine in my hands. Very interesting, your description!