Category Archives: design

why are leaves green?

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Why are leaves green? The most obvious answer is that they contain green pigments, the most abundant being chlorophyll and that chlorophyll absorbs the short and long wavelengths in the visible spectrum leaving the middle wavelengths to be reflected and scattered. However, the deeper question is why should chlorophyll absorb in the short and long wavelengths of the visible spectrum when there is more light available in the middle of the spectrum?

The spectral irradiance of sunlight varies with the time of day, the weather conditions, the time of year, and the latitude/longitude. However, I think it would be reasonable to say that by and large, in most situations, the peak irradiance is in the middle of the spectrum (that which we would normally associate with being green and yellow).

So if one assumes that evolution has produced a perfect engineering solution to this aspect of nature in particular then I think one may expect plants to absorb mainly in the middle part of the spectrum (and this would result in the bluish and reddish wavelengths being reflected and a purplish colour).

So why don’t we have a chlorophyll equivalent that is purple? I have come across a number of arguments.

1. One could go further and say that if a plant wanted to be really efficient it would absorb all wavelengths of the visible spectrum and would therefore appear black. So black, rather than purple, would be the perfect engineering solution. Given that most plants are neither black nor purple then I think we can assume that evolution did not find the perfect engineering problem or that the problem is more complex than we think. For example, it could be that a plant that is black would absorb too much light and overheat. Or it could be that chlorophyll evolved from some earlier light-sensitive chemical and that genetic mutations could lead more easily to chlorophyll than to purple or black pigments.

2. Taking this point further, I have heard it suggested that most plants evolved from earlier plants that lived under water and that absorbed mainly short wavelengths of light (long wavelengths – red – cannot penetrate much more than 1 m of water). These earlier cousins of the modern plant would most likely have been brownish. Indeed, if one looks today ay plants in seawater, green plants are only seen on the surface or at very low depths. So the ancestor of chlorophyll could have been a brown pigment which mutated into green chlorophyll more easily than it could have mutated into a purple pigment.

3. I have also come across the ‘early purple earth’ hypothesis. This suggests that originally most plant life on land was indeed optimally purple and that chlorophyll absorbed to take advantage of those wavelengths that were not already being gobbled up by the dominant species. Subsequently, chlorophyll proved more successful than its purple companion.

4. It could be argued that optimally absorbing light (and being purple) is not the most important thing and that there are other aspects of the problem that are more important. Green chlorophyll could be the optimal solution to this more complex problem.

In short, the real answer is … I don’t know. I am not overwhelmingly convinced by any of the above arguments.

If you enjoyed this post you may like to look at my special christmas post on carrots and why they are orange.

Design is everything and nothing

design, opinions/rants,

It’s possible to say that everything is designed. When we think of design we often think of fashion design or graphic design, or perhaps automtotive design or software design. But everything is designed. When we put a meal together, couldn’t you say we are designing? A chef is a food-designer!! When we are arrange our furniture, aren’t we engaging in interior design? Isn’t a chemist engaging in design at the moulecular level? Thinking like this leads to the idea that design is everything. However, if design is everything and everywhere then it is no thing and nowhere in particular. So if design is everything then it is also nothing. Discuss.

colour choice

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I met a chap from an Advertising Agency today and was surprised when he offered me his business card. He didn’t offer me a single card; he offered me a selection from a fan of cards of different colour.

I chose the purple one and was then surprised when my PhD student told me she has chosen the same colour. A clever experiment in colour preference perhaps? Next time we meet I’ll have to ask him for the data. I hope he is keeping a record of which colour cards are proving most popular.

If you are interested in this you may like to have a look at my colour preference poll. After you take part in the poll (takes only a few seconds) you can see the results of the study so far.

totally colour blind

culture, design, technology, , , ,

I was recently writing about colour blindness in the context of design and noted that most colour blind people see colour – it’s just they have poor discrimination and some colours look the same to them whereas to a so-called normal observers they would look different.

People who don’t see colour at all are rare. But I was just reading about one, Neil Harbisson, a classically trained pianist who has been colour blind since birth. He suffers from a condition called Achromatopsia which means he can only see the world in grey. However, he has recently being used a piece of technology that allows him to hear variations in colours. The eyeborg helps translate colours into sound and transforms the colour information picked up by the built-in camera into sound frequencies. For example, when he looks at a red, for example, he hears an F (= 349.23Hz); if he sees a yellow he hears a G. For more information see http://www.techeye.net/science/technology-helps-man-hear-colours.

I wonder what this would feel like. Of course, synesthesia sometimes occurs naturally. That is, some people can hear colours, see sounds, taste numbers etc. I sometimes think that Kandinsky (the artist who worked at the Bauhaus) may have been synesthesic because of his interest in the relationship between colour and shape. Quite possibly, sensing the world in a way that is different to how most people perceive it may me an advantage to an artist.

colour blind designers?

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Is colour blindness a problem in design? Colour blind is rare amongst females but is very common amongst males. Approximately 8% of all the men in the world have some form of colour blindness. Colour blindness is a bit of a misnomer of colour; most colour-blind people can see colour but confuse colours that so-called normal observers can easily distinguish between. The most common case is red-green colour blindness and such sufferers find it hard to tell reds and greens apart.

 

But does design take this into account sufficiently? One area where there may be a problem is in the gaming industry. I came across the following comment today where someone is reporting a problem using Call of Duty (a game I don;t play but which I understand is quite popular) on the Xbox. Apparently, the Gamertags of all the players are either green if they are on your team, or red if they are an enemy. Oops!! I wonder how much of a problem this is. The problem is probably greatest when colour is used to convey information (as in this case, friend or enemy) rather just for aesthetics (where the information may be conveyed by contrast alone).

any colour as long as it is black

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Famously Henry Ford, speaking of the Model T car in 1909, said “Any customer can have a car painted any colour that he wants so long as it is black.”

Black is, I think, one of the most interesting colours. I recently came across a book – think it was called A History of Black – which was all about this one colour. In my 25 years working in colour perhaps the most frequent question I have ever been asked is “Is black a colour?”

One interesting aspect of black is that it is almost timeless in its ability to be fashionable. This is one reason why it is worn by lots of people who are particularly conscious of colour (because they work in fashion or interior design etc.). It seems strange at first that people who are most interested and aware of colour are more than likely to wear black. Black is a regular occurrence in the attire of my colleagues in the School of Design at the University of Leeds. Given that it’s timeless, it is also safe. There is no danger of being seen in the wrong colour.

I mainly wear brown. I wonder what that says about me?

colour branding survey

design, fun, , , ,

Please take a moment to take part in this colour branding survey: https://www.surveymonkey.com/s/HTJJ5L6

It will only take a few minutes. This is a survey conducted by one of my students in the School of Design (http://www.design.leeds.ac.uk/) at the University of Leeds.

When the survey is complete I will post a comment about the results here for those who are interested.

colourful greeks

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It’s often thought that black, white and grey are mature and sophisticated colours and that saturated reds and yellows are childish colours. Part of the reason for this is that the Romans and Greeks didn’t use colour. All those classic statues we see in museums are achromatic. However. this may be all based on a misunderstanding. At a CREATE conference in Italy last year I first came across the idea that the Romans and Greeks used colour quite extensively but that over the centuries the colour faded. Today I saw this story in the popular press.

An exhibition of work – Gods In Colour: Painted Sculpture of Classical Antiquity – recoloured as it is believed to have originally been features more than 20 full-size colour reconstructions of Greek and Roman works. Currently on show at the Pergamon Museum in Berlin, Germany.

favourite colour

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I was reading on a web page that white is the usual response if you ask people their favourite colour – http://www.pressdistribution.net/14735/apple-iphone-4-white-show-true-colour

I don’t think its true. Most studies show that people’s favourite colour is blue. I have never heard of a study that found white to be the favourite colour. The article was about the iPod though and we all know that the use of white was an inspired choice by Apple. The white earphone leads have become iconic and are part of the brand that consumers buy into by the millions. In fact, I think this is a very interesting phenomenon – there is a lot of research that shows that people prefer one colour to another. But what use is it? Over the last few years my research has focussed on the context of colour preference; that is, which colours would be most effective when used for a particular product (and by extension, for a particular market).

colour blind to traffic lights

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Colour blindness afflicts about 1 in 12 men in the world. Women are far less affected because they have two X chromosomes. Men only have one X chromosome and therefore there is no backup if the gene for good colour vision is damaged or changed. Of course, colour blindness is a misnomer. Very few people indeed are really colour blind and the term colour defective is scientifically more correct. So-called colour blind people have trouble discriminating between colours that the rest of us see as different. Most commonly the difficult is in telling reds and greens apart which is where the term red-green colour blind derives from. Though people need to be able to pass colour-vision test before they can be employed in certain professions (such as being an aeroplane pilot) where colour decisions are critical, everyone is allowed to drive a car. Even though traffic lights are red and green!!

The argument for allowing colour blind people to drive has always been, I think, that drivers quickly learn the positions of lights. Red, is on top, amber in the middle and green on the bottom. However, is that red-amber-green order used everywhere in the world. It is used in the UK where I live. But elsewhere?

Whether to do with the order of the lights or not, several studies have shown that colour blindness is a risk factor in driving. Hence the development of the UniSignal (Universal Signal Light). Developed in South Korea the UniSignal uses different shapes for different colours so that drivers can recognise which light is on whatever the order in the particular city in which they find themselves.

Kandinsky would approve!