4 Replies
Ned Whiteley

Hi Francesca,

The most common form of colour blindness is red/green, as in my case. Although I use both colours regularly in PowerPoint and for Articulate courses with no problems at all, please don't ask me to pick out the number in one of those Ishihara tests as I probably won't be able to:


I generally find that dull colours are easier to see in annotations, especially as they usually provide a better contrast to the background. I can happily read dull red and dull green text, but light, bright red and green text is definitely harder to pick out.

There are varying degrees of colour blindness and so I would suggest producing a quick slide with a range of different coloured annotations and put it out to the community and ask for preferences. Remember, the background colour is also a key part of the equation as well. From my point of view, you can instantly cross off red on green or green on red !

Hope this helps.

Sally Wiedenbeck

There are so many different types of color blindness (and other vision impairments related to color perception). It is not the color itself that matters, but the contrast between the element's color and the color of the background/surrounding color. The contrast checker at contrast-ratio.com will tell you if the contrast between your background color and visual element is high enough to be perceivable.