How to check an image for color blindness
- Drop an image: a chart, map, infographic, game screenshot or website design. A color wheel and a typical chart palette are shown until you do.
- Pick a type of color vision deficiency. The simulated version appears next to the original.
- Lower the severity to simulate the milder, more common forms (protanomaly and deuteranomaly).
- Download the simulated image to share with your team.
Types of color blindness
About 8% of men and 0.5% of women of Northern European descent have some form of color vision deficiency. Most common are the red-green types: deuteranomaly and deuteranopia (weak or missing green cones) and protanomaly and protanopia (weak or missing red cones, which also makes reds look darker). Tritanopia affects blue-yellow discrimination and is rare, and complete color blindness (achromatopsia) is very rare.
The simulation applies the physiologically based model by Machado, Oliveira and Fernandes (2009) in linear RGB, the same model used by Chrome DevTools' vision deficiency emulation. Severity below 100% blends towards normal vision to approximate the anomalous forms. It is an approximation: real perception varies between individuals.
Designing for everyone
Never rely on color alone to carry meaning. Red and green status dots, line charts in similar hues and maps colored only by hue are the usual problems. Add labels, icons, patterns or different line styles, and vary lightness as well as hue. Palettes such as blue and orange remain distinguishable for most viewers. Images are processed locally in your browser.
What is the most common type of color blindness?
Deuteranomaly, a reduced sensitivity to green light, which affects about 5% of men.
Which colors should I avoid together?
Red with green, green with brown, blue with purple and light green with yellow are often confused. Distinguish them by lightness or add labels.
Is this a color blindness test?
No. It shows how images appear to others. To check your own color vision, try the color vision hue test, and see an eye doctor for a diagnosis.