Colour naming experiment

Firstly, sorry for the delay in getting a new proof written. I’ve been travelling, and then got sick on the flight home and was mostly incapacitated for two weeks. And I have deadlines for other stuff that then got in the way.

But one of those deadlines also involves science, and it’s pretty cool so I thought I’d share it with you. I do volunteer work with CSIRO’s STEM Professional in Schools program. As a professional scientist, I am partnered with a primary school and visit the school several times a year to talk to and engage the students with science topics. In past years I’ve mostly done presentations and Q&A sessions, but this year the school science coordinator suggested running a science club with some of the keenest science students from each year.

My Science Club is made of 13 students from years 2 to 6 (so ages 7 to 11). I’m running several experiments with them throughout the year. One of them is actually Eratosthenes’ method of measuring the size of the Earth, modified slightly. I’m getting the kids to measure the length of a vertical stick’s shadow every day at noon. At the end of the year I’ll help them plot the length versus day of the year, and we’ll fit a sine curve and extract the parameters to let us calculate the size of the Earth.

This Monday, I have another Science Club meeting, and I’ve been preparing a different experiment, on colour perception and naming. This is a cool topic that I’ve been interested in ever since I attended an imaging conference and saw some talks about the psychophysics and cultural psychology of colour perception. What I’ve done is to visit a local hardware store and raid their set of house paint sample brochures. Then I cut them up:

Cutting up paint brochures

I had way too many colours, many of which were very similar to others, so I selected a representative subset to try and span as much of the colour space as I could. Then I arranged them and used double sided tape to stick them into manila folders:

Sticking samples into folders

A couple of hours later, and I had 13 folders with identically laid out colour swatches inside:

Colour swatch folders

I used a marker to label all the swatches in each folder with a number. There are 35 swatches:

The 35 colour swatches

Now, here’s the experiment: On Monday in Science Club I’ll give each of the students one of the folders. I’ll also give them a potential list of colour names, with over 100 possible colour names on it:

List of colour names

Their task is to look at each colour, decide which name is the best name for it, and write the colour number on the sheet next to that name. Repeat for all 35 colours. So a lot of the names are going to be left unused. And I’ve included a few write-in slots for any cases where a student is positive that a certain colour really must be called “nasty bruise” or whatever. I’ve been careful to pick names that young children can relate to, and avoid weird things like “heliotrope” and “malachite” that they’ve probably never heard.

The science behind this experiment is that we’re all pretty good and consistent at naming very basic colours like red, and yellow, and blue, but when it comes to naming more subtle shades we are actually highly inconsistent. Is that particular shade of red: rose red, or raspberry, or cherry, or something else? Ask a lot of people and you’ll get a lot of different answers. There are classic studies showing this. (And yes, Randall Munroe of xkcd did a similar thing online a while back and published the results.)

There’s also a study showing that people are inconsistent with themselves, if given exactly the same task a few weeks later. Nearly everyone changes their mind on what certain shades should be called. So this is my experiment with my Science Club! I’m not going to tell the kids that we’ll be repeating this task later in the year. It’ll be interesting to see how closely they can reproduce their own results then, and also how closely their answers align with one another.

Basically, I’m doing something that happens with all good science. I’m replicating an experiment to see if I can reproduce the results. And now that I have this experiment ready to go, I’ll get on to writing up another proof that the Earth is a globe… hopefully within the next few days.

7 thoughts on “Colour naming experiment”

  1. When I first read the subject, I thought of a different thing that you could do with the same swatches how about which is to ask people to group the 35 different colours into the 11 basic Modern English colour names (or however many you have in Australia). In my experience, the boundary between blue and green varies a lot between different people (and we should probably pick another basic colour name in there and have an even dozen). But I think that people are also using ‘pink’ a lot more broadly than in my youth; my 3-year-old is convinced that the middle traffic light is orange, not yellow; and there are probably many other controversies to uncover.

    1. Funny about traffic lights. I’ve only ever heard the middle light being described as “yellow” by non-Australians. Everyone in Australia calls it orange. There definitely are cultural differences in colour names. (Not just anecdotally – I’ve seen a lot of published research in this area.)

      1. Interesting, maybe my 3-year-old is Australian! (Here in the USA[*], we sometimes call it ‘amber’, acknowledging that it's not a pure yellow, but that seems more of a technical term, like the colour words in your experiment.)

        [*] Using the spelling ‘colour’ here is my own idiosyncrasy.

      2. Also, traffic lights in different places (sometimes even different lights in the same city) use actually different wavelengths of light for the middle “going to be red soon” signal.

  2. I’m curious if you’ve accounted for the possibility that one or more of the students may have some degree of colorblindness, diagnosed or not.

    I’d also be curious if this experiment somehow becomes the vehicle for discovering such a condition.

    1. I’m well aware that some of the students may be colourblind. I’ll be asking them beforehand if any of them are aware that they have colourblindness. And yes, if any are not aware, this could be an indicator. I’ve checked with the school and they’re okay as long as I explain it and assure the kids it’s nothing to worry about. I suspect they have to handle this exact issue every now and then.

  3. Colour is complicated. Part of the problem, is that our brains do a lot of pre-processing of colour before it gets to our conscious. We don’t even have ACCESS to the raw colour data, never mind cultural programming. Why is violet a named colour of the rainbow? It’s a TINY sliver of the spectrum! “Gold” isn’t even a colour! Why did ancient Japanese have only one name for green/blue/purple? Even computers have issues. You might THINK RGB & CMYK are universal, but then you hear about advanced specifications that take into account different gamuts. Like LAB and LCH. It’s all quite headache inducing.

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