The human eye can physically perceive millions of colors. But we don’t all recognize these colors in the same way.
Some people can’t see differences in colors – so-called color blindness – due to a defect or absence of the cells in the retina that are sensitive to high levels of light: the cones. But the distribution and density of these cells also vary across people with “normal vision” causing us all to experience the same color in slightly different ways.
Besides our individual biological makeup, color perception is less about seeing what is actually out there and more about how our brain interprets colors to create something meaningful. The perception of color mainly occurs inside our heads and so is subjective – and prone to personal experience.
Take for instance people with synaesthesia, who are able to experience the perception of color with letters and numbers. Synaesthesia is often described as a joining of the senses – where a person can see sounds or hear colors. But the colors they hear also differ from case to case.
Another example is the classic Alderson’s checker-shadow illusion. Here, although two marked squares are exactly the same color, our brains don’t perceive them this way.
The culture of color
Since the day we were born we have learned to categorize objects, colors, emotions, and pretty much everything meaningful using language. And although our eyes can perceive thousands of colors, the way we communicate about color – and the way we use color in our everyday lives – means we have to carve this huge variety up into identifiable, meaningful categories.
Painters and fashion experts, for example, use color terminology to refer to and discriminate hues and shades that to all intents and purposes may all be described with one term by a non-expert.
Different languages and cultural groups also carve up the color spectrum differently. Some languages like Dani, spoken in Papua New Guinea, and Bassa, spoken in Liberia and Sierra Leone, only have two terms, dark and light. Dark roughly translates as cool in those languages, and light as warm. So colors like black, blue, and green are glossed as cool colors, while lighter colors like white, red, orange and yellow are glossed as warm colors.
The Warlpiri people living in Australia’s Northern Territory don’t even have a term for the word “color”. For these and other such cultural groups, what we would call “color” is described by a rich vocabulary referring to texture, physical sensation and functional purpose.
Five key colours
Remarkably, most of the world’s languages have five basic color terms. Cultures as diverse as the Himba in the Namibian plains and the Berinmo in the lush rainforests of Papua New Guinea employ such five term systems. As well as dark, light, and red, these languages typically have a term for yellow, and a term that denotes both blue and green. That is, these languages do not have separate terms for “green” and “blue” but use one term to describe both colours, a sort of “grue”.
Historically, Welsh had a “grue” term, namely glas, as did Japanese and Chinese. Nowadays, in all these languages, the original grue term has been restricted to blue, and a separate green term is used. This is either developed from within the language – as is the case for Japanese – or through lexical borrowing, as is the case for Welsh.
Language and colour
The way we perceive colours can also change during our lifetime. Greek speakers who have two fundamental colour terms to describe light and dark blue – “ghalazio” and “ble” – are more prone to see these two colors as more similar after living for long periods of time in the UK – where these two colours are described in English by the same fundamental colour term: blue.
This is because, after long-term everyday exposure to an English speaking environment, the brain of native Greek speakers starts interpreting the colors “ghalazio” and “ble” as part of the same color category.
But this isn’t just something that happens with color, in fact, different languages can influence our perceptions in all areas of life. And in our lab at Lancaster University we are investigating how the use of and exposure to different languages changes the way we perceive everyday objects. Ultimately, this happens because learning a new language is like giving our brain the ability to interpret the world differently – including the way we see and process colors.