As data professionals, we’ve all heard it:
“Don’t use red and green in dashboards – people with colour vision deficiency won’t be able to tell the difference.”
Fair. But incomplete.
The truth is, you can use red, amber, and green – responsibly.
Why RAG Still Works
RAG status indicators (Red, Amber, Green) are deeply embedded in business reporting. Executives love them.
✅ They’re familiar
✅ They communicate urgency at a glance
✅ They help people act faster
Rather than banishing them, we should be learning how to use them accessibly.
The Colour Vision Challenge
Around 8% of men and 0.5% of women live with some form of colour vision deficiency (CVD) – the more accurate term for what’s often called “colour blindness.”
The most common type, deuteranopia, makes it hard to distinguish red from green – especially in continuous gradients or when saturation is low.
Better Design for Everyone
Here’s how to make RAG work and be inclusive:
✔ Use discrete colours, not gradients
Avoid continuous red–green scales where shades blend into each other. Go for clear, separate colour blocks.
✔ Pick colour-blind-safe palettes
The IBCS palette is a great example. You can test your colours using ColorOracle.org – a free, simple tool that shows you how your palette looks under different types of CVD.
✔ Add tooltips or labels
A small label like “Red = Critical” or hover text ensures users understand the meaning, even if they can’t distinguish the colour.
✔ Give users options
Let them toggle labels or access alternative views – small changes that make a big difference.
Real Example
I tested two versions:
- A diverging red–green gradient (looked fine until I applied a CVD filter – then, not so much)
- A discrete RAG scheme using the IBCS palette, which passed the accessibility check
Both showed status. But only one worked for everyone.
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Thanks for reading – and if you found this helpful, consider sharing it with a colleague or friend who still thinks red-green gradients are a good idea 😉
#DashboardDesign #ColourAccessibility #TableauTips #KPIReporting #InclusiveDesign
