When you create slides in PowerPoint, do you consider colour contrast? A recent poll conducted on LinkedIn showed that only 5% of people use a contrast tool to check how easy it is to read their content.
I don’t know about you, but recently I have seen some very hard to read PowerPoint slides. Imagine losing out on business because a potential customer couldn’t read your slides, or social media posts, for that matter! This is why colour contrast is so important. What do we mean by colour contrast? How easy it is to see text, depending on the colour of the text and background. The image below shows some examples.
I’ve always had an interest in colour. Many years ago, I worked in the automotive industry. My job was to colour match the fabric for the interior of cars. When a new roll of material arrived on site, I had to assess it to ensure the colour was within tolerance. The company made interior parts for companies including Rover, Land Rover, Toyota, Ford and Jaguar. These companies did not want the fabric on one door to look different from another door.
Colour Tests
On my first day on the job, I was introduced to the Farnsworth Munsell 100 hue colour test. The test consists of 4 trays containing 85 removable colour reference caps of incremental hue variations spanning the visible spectrum. The colour caps were removed and put in random order. The test involves putting the caps back into hue order between two fixed hues. This is repeated for each of the four trays.
I passed with zero errors. I had an eye for colour! My boss, a man, told me that he rarely saw this result. Why is it important to say to you my boss was a man? Because men are more likely to experience colour blindness than women. According to X-rite, a manufacturer of spectrophotometers (scientific equipment to measure colour), 1 in 12 males has a form of colour blindness compared with 1 in 225 women; a big difference! I worked in a male-dominated environment. Perhaps that was why my boss had never seen anyone get a perfect score before.
If like me, you’re curious, you can take an online test on the X-rite website. Here’s an example of the test before and after completion. On the left is the test before you start and on the right is the completed test.

And, here’s the result below. Although I now wear glasses, my colour assessment is still as sharp as twenty-something years ago!

What does all this have to do with PowerPoint slide design?
We perceive colour differently, and what’s more, some people with colour blindness only see in black and white or greyscale. The most crucial aspect to consider when creating a presentation is our audience, so how can we cater for colour disabilities when we design PowerPoint slides?
One way is to consider the contrast between the colour of your text and the background colour. There are several online tools you can use. The assessment is based on the Web Content Accessibility Guidelines (WCAG) 2.0.
These tools allow you to enter the colour of your text and background using various colour measurements units. If this is all new to you, start with Contrast Checker because this tool allows you to use RGB colour units (Red, Green, Blue) used in PowerPoint. Below is the output from Contrast Checker. As you can see, this combination ticks all the boxes.

The pass or fail criteria are based on different font sizes, the brightness and colour difference and how readable your text is in greyscale (for people who cannot see in colour).
Others tools available are WebAim and Coolors.
I’d love to hear your feedback on these tools and if you’d like to know more about how I can help you with your PowerPoint slide, check out my Services page!