The green on your “Paid” badge and the red on “Overdue” can be the same colour.
About 1 in 12 men of Northern European ancestry have a red-green colour vision defect. Flip through the lenses below, then test your own palette and let the page repair it.
01 / The problem
An ordinary invoice list, seen through five lenses
InvoicesTypical colour vision
02 / Your turn
Test any five colours
Pick a preset or type your own hex codes. Each row shows what the palette becomes under one type of vision. The greyscale row is for reference and is not scored.
Rule of thumb used here: two colours count as “too close” when their CIE76 distance (ΔE) under a simulated lens is below 15. It is a quick screening heuristic, not a clinical test. Whatever the result, never rely on colour alone: add labels, icons or patterns.
Sources
Prevalence: MedlinePlus Genetics, Color vision deficiency (about 1 in 12 males and 1 in 200 females with Northern European ancestry; lower in most other populations).
Simulation matrices (dichromacy, severity 1.0): Machado, Oliveira and Fernandes, IEEE TVCG 15(6), 2009, Table 1. Applied here to linearised sRGB.