Category Archives: design

would you like pink chocolate?

About 80 years ago the Milkybar was introduced by Nestlé. Since then, chocolate has broadly speaking been one of three colours: dark, milk and white. Today I read that a new colour of chocolate has been developed which is claimed to be the first new natural colour of chocolate since Nestlé’s innovation. The beans are grown in Ivory Coast, Ecuador and Brazil and the new chocolate, which is being referred to as ruby chocolate, has been underdevelopment for just under a decade. Apparently this new chocolate has a natural pinkish colour and a berry flavour. I suspect the manufacturers are choosing to call it ruby chocolate rather than pink chocolate because the latter sounds childish; they probably want to market this new chocolate in the upper price brackets and emphasize that its colour is natural (there are plenty of pink children’s sweets out there that are full of artificial colorants).

Digitizing Traditional Cultural Designs

A bojagi is a traditional Korean wrapping cloth.

There is currently interest in re-using traditional and cultural designs in modern commercial applications. The bojagi is one of these traditional designs that could be reinvented and hence reinvigorated. But how can a designer create bojagi patterns for use in new digital design?

Working with Meong Jin Shin I developed a software tool that can create a wide range of different bojagi. We identified 8 different classes of traditional bojagi as shown below:

We then created a software tool that would allow a user to create new bojagi which would have the same visual characteristics as one of these 8 traditional classes.

We had some designers in Korea evaluate the tool and they were quite impressed. Although in this study we worked with Bojagi, in fact we were interested in exploring the general method of using digital tools such as this one to allow users to explore traditional designs and to use them in their contemporary design work. The ideas could be easily extended to cover other traditional designs such as tartan. The software could also be added to a package such as Adobe Photoshop as a plug-in.

You can read the full paper that we published here.

Shin MJ & Westland S, 2017. Digitizing traditional cultural designs, The Design Journal, 20 (5), 639-658.

Does context affect colour meaning?

One of the reasons that colour is such a powerful and important property is that it conveys information. Colour imparts meaning. If you see a big red button you may understand that something important or dramatic may happen if you press it. If someone is wearing bright yellow clothes it might imply something about their personality. Take a walk into a toy store and notice the swathes of pink in the girls’ section (though note that I don’t imply that this is a good thing; indeed, I would refer you to the pink stinks campaign in order that you may become a right-thinking person). But it is clear that the manufacturers of the toys believe that the colour pink will indicate that these are toys for girls and that its use may even make girls want to have these toys. If you see two washing-up liquids and one is green and one is yellow you might think that they would smell of apples and lemons respectively before you even open them! Colour sells. And part of the reason that colour sells is that it is informative. Colours have meanings.

But does colour per se have meaning or does colour only have meaning when it is an attribute of a product? The colour red on an emergency stop button may have one meaning but the colour red on the soles on Louboutin shows may have an altogether different meaning. And, of course, colours mean one thing in one culture but another in a different culture; black is commonly associated with death in the West but in China and some other countries in Asia death is more commonly associated with white. Nevertheless, I do believe that colour per se, that is colour in an abstract sense, does have meaning and there are a number of studies out there that tend to support me (though some social scientists, in particular, who would disagree).

What I mean by this is that if we take a culture, such as the UK, then a colour such as red will be associated with various ideas and concepts to varying degrees of strength. Red may take on different meanings when applied to different products (that is, in context). But is there any relationship between the abstract colour meaning and the product colour meaning? This is the question that Seahwa Won (who was a PhD student working with me) and I asked each other that led to a piece of work and an academic paper.

If there is no relationship between abstract colour meanings and  product colour meanings then it might mean that there is little practical or commercial value in studying abstract colour preferences (though it may still be worthy of study). On the other hand, if there is a relationship between abstract colour meanings and  product colour meanings then knowing the former may help us to predict the latter in a wide range of circumstances. To carry out our study we used scaling (I have blogged about some aspects of scaling before) where we try to quantify the perceptual response of participants to physical stimuli. For example, we show people a colour patch on a display screen and then below this there is a slider bar which allows the participants to respond whether the colour is warm, for example, or cool. We do this for lots of colours and lots of participants (nobody said colour science was easy!!) and then we can average these and have a warm-cool scale along which we can place all the colours. When we do this, for example, we find that participants think red is much warmer than blue. However, what Seahwa and I also did was to repeat this type of experiment with different colour products rather than simple colour patches. Would participants place a red toilet roll on the same point on the warm-cool scale as the red colour in an abstract sense? If they would then we can conclude that abstract colour preferences and product colour preferences are related.

We did this for quite a few different scales (warm-cool, expensive-inexpensive, modern-traditional, etc.) and for for a few different colours. The figure below shows the results when we explored the masculine-feminine scale. Look at the left-hand part first, where it says chip along the bottom. Chip indicates the abstract colour meanings (for example, when participants view a simple square or chip of colour). Note that participants scale beige, red and yellow as being feminine colours whereas black, blue and green are more masculine colours. Now look at the right-hand part of the figure, where it says crisps (in the UK a crisp is something you buy in a bag to eat; Americans may call these potato chips). When we showed crisp packets that were differently coloured the masculine-feminine scale values were almost the same as for the abstract colours themselves. We found strong relationships between abstract colour meanings and product colour meanings more often than not.

Our findings are broadly compatible with an earlier study by Taft in 1996 who found that there was no significant effect of context on colour meaning in the majority of cases. We did find some effects of context though. For example, black-coloured medicine was perceived as being more feminine that the abstract colour black itself.

We published this paper in 2016 in the journal Color Research and Application and you can read the paper in full here.

Won S & Westland S, 2017. Colour meaning in context, Color Research and Application42 (4). 450-459.

Consumer Colour Preferences

How does your personal colour preference affect the colour of the things that you buy?
It is well known that people prefer some colours more than others. Personally, I much prefer red to blue. But I am probably in a minority. Many studies have shown that blue is the most popular hue with yellow being one of the least popular hues. But this is when we think of colour in an abstract sense. But what about when colour is applied to a product: a pair of trousers, a toothbrush, a fidget spinner? Well, my favourite colour is red but I have never owned a pair of red trousers. I tend to buy buy blue or brown trousers even though I don’t really like the colour blue in the abstract sense. But are there products where, if we were presented with a choice in colour, we would tend to buy the colour product that matches our abstract colour preference? This is the question that I set out to answer answer two years ago with my colleague Meong Jin Shin. We carried out an experiment over the internet where we presented people with a choice of products in different colours and asked which they would buy given the choice. They were presented with images a little like the one below:

After we asked participants which product they would buy for a number of different products we then asked them what their favourite colour was in an abstract sense (we showed a number of colour patches on the screen and asked the to click on the one they liked best). Our hypothesis was that for some products participants would tend to select products that closely matched their most preferred abstract colours but that for some other products we would not find this.

This is exactly what we found. For some products, such as bodywash, we found that people tended to prefer a particular colour for the product (in this case, blue). The figure below shows the results for bodywash. The rows represent the colour of the products and the size of the circle in each row represents the proportion of people who generally preferred either red, orange, yellow, green, blue or purple that selected that product colour. As you can see below the majority of people chose a blue bodywash no matter what their abstract colour preference was.

However, for the toothbrush product a very different picture emerged. As shown below, people who liked red generally tended to select a red toothbrush and people who preferred purple tended to select a purple toothbrush. For example, 41% of people who preferred green selected a green toothbrush.

So sometimes people’s personal colour preference could be used to predict which colour product they would choose to buy given the choice (and sometimes it couldn’t be). How could this be useful? Well, if we could predict which products where this is true then it would suggest that a multi-colour marketing strategy could be appropriate. Also, imagine you are in a supermarket and you are presented with an offer – 50% off toothbrushes today – and alongside this you see a red toothbrush. If red was your favourite colour then there might just be a little more chance you would accept the proposition. If a supermarket could predict a consumer’s personal colour preference …. [more of this in a later post].

This paper was published in 2015 in the Journal of the International Colour Association. You can read the full paper for free here.

Westland S & Shin M-J, 2015. The Relationship between Consumer Colour Preferences and Product-Colour Choices, Journal of the International Colour Association14, 47-56.

colour lighting

Very excited with the temporary installation of our new spectral lighting system at Leeds University. Whereas most coloured lights are based on RGB, we have a system that has a lot of spectral control (it works by having 11 different coloured LED primaries). We have several PhD students who are using these lights with their research. Nic and Yiting are looking at the effect of light and colour on alertness and also on impulsivity. Meanwhile, Soojin (pictured) is looking at the effect of colour on creativity (though in her study we won’t be using really saturated colours like those shown in the pictures). Hoping for some great publications on this soon. However, if you are interested in whether coloured lighting can affect heart rate and blood pressure take a look at our AIC publication (pdf) that we presented in Tokyo in 2015.

UK favourite car colours

The top three favourite car colours in the UK in 2016 were white, black and grey (in that order). White has been the best seeing colour for four years which is interesting because it never used to be popular in the UK. Car salesman used to refer to the colour as three-week white because it took three weeks longer to sell a white car compared with other colours. But it’s 10 years now since a chromatic colour was number 1.

For further details see here.

red rage in schools


Staff at a primary school in Dundee want to change the colour of the uniform because they think the red colour could affect children’s behaviour. According to the Headmistress Gillian Knox:

‘Red is often used to energise body and mind, and some research indicates that it can increase heart and breathing rates. [This is] not the calm, relaxed learning state we hope to achieve. A recent study linked red to impaired performance on achievement tasks.’

Pupils currently wear a bright red jumper or cardigan with grey trousers or skirt. But teachers want there to be only ‘small amounts’ of red – such as in the school tie.

However, although statements such as this – that red raises heart rates – are all over the red and often cited as facts (as in ‘everybody knows’) in fact there is very little evidence that looking at red can affect heart rates. We ran a study at University of Leeds last year and found no statistically significant effect of the colour of light on subjects’ heart rates or on their blood pressure. A review of the literature reveals little evidence: there is a PhD thesis from California from about 1950 that nobody can get hold off and a study with mentally handicapped children in the 80s. That’s it. Light certainly affects us physiologically but it is far from fact that red raises blood pressure.

changing button colour increased conversion


It seems that only recently companies are carrying out what is known as split testing or A/B testing. Put two designs of a web site out and see which does best. Recently one company did just that. They had one web site with a green call-to-action button (as shown above) and another with a yellow call-to-action button. Changing the call-to-action button from green to yellow resulted in a 187.4% increase in conversions to their website. Is there some effect that yellow light could have compared to green? For example, could yellow light make users more impulsive?

According to Erika Dickstein it may be nothing to do with yellow at all but simply to do with the contrast – the yellow stands out better and therefore is more noticeable. Certainly more research is needed in this area.

light that changes colour with your mood


The future of lighting is LEDs and that means more colour. There are many advantages of LED lighting over tungsten or even fluorescent lights not least of which is the opportunity for more colour. I have noticed all of the new buildings on the campus at the University of Leeds are equipped with coloured lighting. The Laidlaw library – and even the new car park – is illuminated at night in an eerie purple glow.

The Syska SmartLight plugs into a standard socket but then can be controlled using the “Syska Rainbow LED” app for your Android or iOS phone or tablet.

I want one. But I am not sure they are on sale in the UK. More details here.