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Improving accessibility through IoT for people with colour blindness

Today marks the 250th anniversary of World Colour Blind Awareness Day

Sam Bunyan
Sam Bunyan

Sep 06, 2022

Today is World Colour Blindness Awareness Day and this piece will be your go to for understanding why this awareness is still so important and how the condition affects people across the globe. We will also look at how colour blind people are accounted for in the design of modern-day products, but also why there is still room for improvement across the board.

What is Colour Blindness?

Colour blindness (colour vision deficiency) is the decreased ability to see colour or differences in colour. It can impair tasks such as selecting ripe fruit, choosing clothing, and reading traffic lights.

When was Colour Blindness discovered?

English chemist, John Dalton, known for introducing atomic theory into chemistry, wrote in 1794 about his own colour blindness. He believed he had blue ink in his eye and asked for his eye to be dissected when he died. This was done, but those who did found his affected eye was fine. After further study, they did however discover that one of his green cones behind his eye’s retina was faulty, which became the catalyst for understanding how colour blindness occurs.1

What causes Colour Blindness?

Every human eye has the retina which is responsible for sensing the light you see. Behind the retina, you have rods which help you see in low light conditions and your cones which help you see detail and colour in everyday life. Most people have three of these cones, but if 1 of these three cones is faulty or missing, then you will develop a colour deficiency.2

Trichromacy means you have normal colour vision where cone cells are functioning correctly.

Anomalous trichromacy is the situation where you have 3 cones behind the retina, but one of these cone cells is defective resulting in a colour vision deficiency. Within this type of vision, you also have the exact condition types Protanomaly (reduced sensitivity to red light), Deuteranomaly (reduced sensitivity to green light-most common) and Tritanomaly (reduced sensitivity to blue light – extremely rare). To see what these different types of colour blindness look like, please visit this link.

Dichromacy is when a person only has two cone cell types, which results in a specific section of the light spectrum not being perceived by the brain at all. People with protanopia are unable to perceive any ‘red’ light, those with deuteranopia are unable to perceive any ‘green’ light and those with tritanopia are unable to perceive any ‘blue’ light.

Monochromacy / Achromatopsia is where people can see no colour at all, and their world consists of different shades of grey ranging from black to white. Achromatopsia is extremely rare, occurring only in approximately 1 person in 33,000 and its symptoms can make life very difficult. Usually someone with achromatopsia will need to wear dark glasses inside in normal light conditions.3

How do people suffer from colour blindness?

Colour blindness in most cases is passed down genetically – especially with the red/green and blue/yellow colour blindness types. Inherited blue/yellow colour blindness is very rare because it is inherited differently to red/green types. The red/green colour blindness type for example is carried down on the X chromosome which is the main reason that many more men are affected than women. If you wish to do an online colour blindness test, you can try the PseudoIsochromatic Plate (PIP) Colour Vision Test.

How many people are affected?

Colour blindness affects approximately 1 in 12 men (8%) and 1 in 200 women. In the UK there are approximately 3 million colour blind people (about 4.5% of the entire population), most of whom are male. Worldwide, there are estimated to be about 300 million people with color blindness, almost the same number of people as the entire population of the USA!

Are Colour Blind people accounted for enough in the UK?

There is little doubt that many companies have found more and continuously innovative ways to improve accessibility of products in recent years, but there remains room for improvement. With regards to colour blindness, software changes on certain products have made more people realise that there are other options to colour for effective design. For example, electrical products showing a blinking light for when they need charge, rather than simply a red light. Furthermore, a solid light when it is charged makes it easy to understand what is going on without the need for colour differentiation. The same can be said for using crosshatches or dots to fill in bars on graphs rather than just colours – providing such options for customisation is key to making products accessible. iPhones, Trello, and recent Call of Duty games have been the best at doing this in recent years.4

Why is there still room for improvement?

There is still an argument to suggest that many underestimate the amount of people living with colour blindness in the UK and abroad. Although there are large tech companies meeting up to define accessibility standards for IoT devices, there remains a lack of cohesive effort towards the same for product accessibility. With there being a lack of enforcement / regulation of companies doing this in the UK, it has become vital that each company takes stock to reflect on the accessibility of their products with all that we have discussed today in mind.5 Customisable options for any lights being used or moving more towards designing the light’s behaviour rather than its colour (flashing for needing charge) can be smart ways to improve things for people of different colour blindness. For example, how the Apple TV uses a single white LED to communicate status. Currently, there clearly remains a need for greater consistency across manufacturers to take colour blindness into account.6

What is being done at Switchee to improve our products’ accessibility?

At Switchee, although we accept its an ongoing mission to make sure our products meet high standards for accessibility, we have already reviewed and improved our web UI to ensure its fully functional for colour-impaired users and we intend to do the same for our thermostats. We also have consulted individuals who suffer from colour blindness over the graphing used on our internal and external-facing platforms to make sure their appearance is not an inhibiting factor to such users who are analysing the data for different purposes. In the coming months, in addition to making sure our partially sighted and blind users are able to control their heating system via our mobile app, we will seek to make sure any newly designed hardware models take into account better ways of designing status light changes - rather than just reflecting different statuses via different colours. We’re also hoping to bring onboard more feedback from residents with colour blindness over the coming months to ensure our new products have their level of accessibility checked.  

In closing, I hope this article has improved your understanding of colour blindness in the UK and abroad. If just one reader goes away with a desire to suggest roadmap items for their company’s products which will improve their accessibility, then this has been a successful piece. This is exactly what we’re hoping to do at Switchee in the coming months and look forward to sharing those developments with you soon.

  1. Science and Industry Museum, 2019, ‘John Dalton: Atoms, Eyesight and Auroras’, URL [], accessed 06 September 2022

  2. Hosts Josh Clarke & Charles W. “Chuck” Bryant and Producer Jerome Rowland (September 2018) ‘What is color blindness?’ [podcast], Stuff You Should Know, iHeartRadio, accessed 6th September 2022

  3. Colour Blind Awareness Organisation, 2022, Types of Colour Blindness, URL {] , Accessed 6th September 2022

  4.  Artiss D (2021), Colour Blindness: Do technology companies do enough to help?, The Big Tech Question, URL [], accessed 6th September 2022.

  5. Ibid
  6. Ibid

Sam Bunyan

Sam works at Switchee as a Product Manager. He coordinates multi-functional teams at Switchee towards developing smart-home devices used by residents in rented homes and the internal cloud platforms which enable our Operations team to support them.

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