Monthly Archives: May 2016

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.

Has technology for Harry Potter’s Daily Prophet just arrived?

I believe that print as we know it is dead. I know that there are some arguing that print is having a resurgence – just as there are those who think that vinyl is on the way back for music – but reports that physical books are gaining ground at the expense of digital are just plain wrong as is explained in this article. I saw this before with digital images where people argued that digital images would never replace traditional photography because of quality and price. Well, of course, we know that the quality of digital images increased and the cost of getting them decreased (when I was a student in the 80s it would have been bizarre to imagine that everyone would have a couple of cameras on them at all times) – but it was not this that killed traditional photography and eventually put the giant Kodak out of business. What killed traditional photography was when you could go to a gig, take a photo, and share it almost instantly with your friends around the world. Traditional photography could never compete with this.

Some people prefer reading print to looking at a screen though I am not one of them. But imagine when an e-document feels like paper, is light and flexible, but you can carry a whole newspaper with you (not to mention all the novels you have ever read) by carrying just one piece of it. And it looks just like print.

E ink, the company behind the pigment-based, low-energy monochromatic displays found in many of today’s popular readers has worked out how to create up to 32,000 colours using almost the same technology. For the first time they can create colours at each pixel using yellow, cyan, magenta and white pigments. The new display is 20-inch with 2500 x 1600 resolution. The image below is rendered in this way. This leads to the possibility of having coloured moving images made out of ink – just like the Daily Prophet in the Harry Potter movies. Well, not quite like that yet. But it’s coming. More details here.


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.

RGB displays are more complicated than you think


Most people assume that display screens are based on RGB – that is the amount of red, green and blue light emitted is controlled in three signals. We tend to think that there is an RGB ‘value’ at each pixel. However, the reality is a bit more complicated. The picture above is a close up of the sort of display on the Samsung Galaxy S phones, as well as the Nexus One. It is called an RGBG pentile layout. This layout was introduced because our eyes are more sensitive to green light (so green pixels don’t need to be as physically large to appear just as bright to our eyes). However, it means that the ‘pixel’ in a standard AMOLED display consists of 8 colours: RGBG on top of BGRG. Some people claim this leads to less sharp images compared to the standard RGB displays of LCD displays (see below) that are sometimes referred to as real-stripe displays.


Some of the AMOLED displays have an RGBW layout, which adds a white subpixel next to the standard RGB subpixels. This allows the display to have an edge in brightness due to a dedicated white subpixel. With that advantage the backlight doesn’t need to be as bright, which saves battery since the backlight is a major user of battery in a mobile device. There is also Samsung’s latest Super AMOLED display technology that has a new subpixel arrangement called the Diamond Pixel. The first phone to use this pentile type was the Galaxy S4. There there are twice as many green subpixels as there are blue and red ones, and the green subpixels are oval and small while the red and blue ones are diamond-shaped and larger (the blue subpixel is slightly larger than the red one).

Displays are much more complicated and varied than you might think. One consequence is that it is not so easy to compare the resolution of different displays technologies beacause they vary in what they call a pixel.

What colour is your city?


I came across an interesting blog by Tom Wolley – a freelance illustrator based in West Yorkshire who specialises in illustrated maps and hand lettering – who developed an illustrated colour may of Leeds (which happens to be where I live). What is particularly interesting is that Tom describes his process somewhat. It is well worth looking at and I think his final design (shown above) is rather nice. The yellows and blues are derived from the classical colours of Leeds and Yorkshire although somewhat more muted.

It makes me think. Are certain colours associated with places? Or even with districts? A recent paper by Willem Coetzee and Norbert Haydam at CAUTH 2016 (The Changing Landscape of Tourism and Hospitality: The Impact of Emerging Markets and Emerging Destinations) looked at this. Their paper was called – Colour association test as a target market analysis technique at an emerging destination – an exploratory study. They used colour association as a market analysis technique to measure tourism demand in a small town. The results indicated that different segments of the market had different associations of colour for the same destination.

cigarette packaging colour


New regulations – from 20 May 2016 – will see all cigarette packaging in the same drab green colour.colour with other standardised features such as opening mechanism and font, and with 60 per cent of the casing covered by text and images showing how smoking affects your health. The decision was made in Parliament on 15 May last year.

They have also been told to get rid of any misleading information from cigarette packs, and have been prevented from using words such as ‘organic’, ‘natural’ or ‘lite’, which could lead consumers to believe there is a healthy smoking option.

Further information can be found in this article in The Independent.

The images shown above are from a similar scheme in Australia.

do glasses for colour blindness work?


For a while there have been coloured lenses on the market that claim that to make colour blindness better. I have my doubts about this. I have tested some of these glasses in my own research and found that they do not work. So I was interested to hear of work by Rebecca Mastey and Richard Schultz at University of Wisconsin-Green Bay that also finds that the products do not work. The researchers tested products from with 27 men with genetically confirmed red-green colour blindness.

The O2 Amp glasses showed some improvement with deuteranomalous observers and deuteranopes, no improvement was found for protonopes whilst the EnChroma glasses had no significant impact on the red-green colour discrimination of any of the participants. The work was presented at the annual meeting of the Association for Research in Vision and Ophthalmology in Seattle.

“The data confirm that these glasses don’t work,” says Dr. Carroll. “In fact, they make some aspects of your vision worse.”

Out of interest, there is also this personal story about a guy with anomalous trichromacy who tested some glasses from EnChroma and fond they made no difference at all.