Estimate how many users are affected by a colour-dependent interface.
Colour vision deficiency is X-linked, so prevalence among men is roughly twenty times that among women. On a service with a hundred thousand users, several thousand cannot reliably distinguish red from green. WCAG requires that colour is never the sole means of conveying information, and adding an icon or label costs almost nothing compared with the share of users it serves.
Color Blindness Simulator
Affected users = male users × male prevalence + female users × female prevalence
Affected users = male users × male prevalence + female users × female prevalence Colour vision deficiency is X-linked, so prevalence among men is roughly twenty times that among women. On a service with a hundred thousand users, several thousand cannot reliably distinguish red from green.
WCAG requires that colour is never the sole means of conveying information, and adding an icon or label costs almost nothing compared with the share of users it serves.
This calculator takes 4 inputs: Monthly users, Share of users who are male, Deficiency modelled, Indicators conveyed by colour alone. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.