Tag Archives: colour

light that changes colour with your mood

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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

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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.

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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?

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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.

do glasses for colour blindness work?

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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.

The future of colour is quantum

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Although our digital displays can show literally millions of colours in fact they show us less than half of the possible colours in the world. This is partly because of the reliance on trichromatic devices – what you probably know as RGB. No matter how we choose them, it is impossible to mix together three colours and make all of the other colours. This is despite this embarrassing statement on the BBC website:

Red, yellow and blue are primary colours, which means they can’t be mixed using any other colours. In theory, all other colours can be mixed from these three colours.

This is just plain wrong. It is not the case that in theory, all other colours can be mixed from these three colours. In theory, and in practice, they cannot.

But I digress. The point is that using a three-colour primary system – a trichromatic system – is never going be able to reproduce all of the possible colours in the world. But even if we do use three, we could do better than the current TVs, phones and tablets on the market if we could improve our technology. The problem is that the red, green and blue lights in these displays are not as bright and colourful as they could be. That is where quantum dots come in.

Quantum dots are tiny crystals that can be precisely tuned to efficiently produce very specific colours. The crystals are grown from a mixture of various semiconductor materials and liquid solvents. By carefully controlling the conditions, engineers can adjust the size of the crystals, which determines the wavelength of the light that the crystals emit. Smaller quantum dots, with a diameter of two nanometres (two billionths of a metre) or so, emit short-wavelength, or blue, light. Bigger dots, with diameters closer to eight nanometres, produce light that’s nearer the long-wavelength, or red, end of the spectrum. We can expect to see new technology on the market soon offering brighter and more colourful displays.

Colour: Art and Science

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I run a module at the University of Leeds called Colour: Art and Science. For me colour is a classic meta-discipline and understanding of colour requires and appreciation of ideas from lots of different academic fields. So I like to present a very multi-disciplinary perspective of colour and I have students enrol from all sorts of different departments in the University which is a lot of fun. One of the main reasons I run this blog is as a resource for those students.

So I was interested to just come across this Brief History of Colour in Art by Sarah Gottesman which covers some of the same stuff that I talk about.

In the same vein I came across this discussion by @CINEMAPALETTES about cinema colour palettes that shows how colours are used to set the mood of iconic films.

The redder the male, the more successful it is.

redbird

According to Joseph Corbo, an associate professor of pathology and immunology at Washington University, the genes affecting red coloration belong to a wider family of genes involved in detoxification. Redness may be a sign of a robust, quality mate who can easily cleanse harmful substances from his body.

“In many bird species, the redder the male, the more successful it is at finding mates,” – Joseph Corbo.

For more see http://www.deccanchronicle.com/science/science/200516/researchers-solve-mystery-of-red-colour-in-birds.html