Accessibility check
Color Blindness Simulator for Palettes & Images
Simulate protanopia, deuteranopia, tritanopia and achromatopsia for a palette or image, and find color pairs that people with color blindness may confuse.
Colors to test
Typical vision
How most people see these colors.
Protanopia
2 pairs may be confusedNo red-sensitive cones: reds look darker and drift toward brown and olive.
- #2CA02C and #FF7F0E look alike
- #1F77B4 and #9467BD look alike
Deuteranopia
2 pairs may be confusedNo green-sensitive cones: reds and greens are hard to tell apart.
- #D62728 and #2CA02C look alike
- #1F77B4 and #9467BD look alike
Tritanopia
Every pair stays distinguishableNo blue-sensitive cones: blue and green, and yellow and pink, blur together.
Achromatopsia
4 pairs may be confusedNo color vision: only differences in lightness remain.
- #D62728 and #1F77B4 look alike
- #D62728 and #9467BD look alike
- #2CA02C and #9467BD look alike
- #1F77B4 and #9467BD look alike
Uses the Machado, Oliveira & Fernandes (2009) model at full severity. Milder, more common forms look closer to typical vision.
How to use this tool
About 1 in 12 men and 1 in 200 women have some form of color vision deficiency. Enter your palette or upload a screenshot to see it through four types of color blindness. The checker also flags pairs that look distinct to you but become nearly identical for each type, which matters for charts, status colors and links.
- 1 Enter your palette colors or upload an image.
- 2 Compare how each type of color vision sees them.
- 3 Fix flagged pairs by changing lightness, not just hue.
Frequently asked questions
Which types of color blindness are simulated?
Protanopia (red), deuteranopia (green), tritanopia (blue) and achromatopsia (no color). The red–green types are by far the most common.
How accurate is the simulation?
It uses the widely cited Machado, Oliveira and Fernandes (2009) model at full severity. Real perception varies, and milder anomalous trichromacy looks closer to typical vision.
How do I make colors distinguishable for everyone?
Give important colors different lightness, not just different hue, and pair color with text, icons or patterns so meaning never depends on color alone (WCAG 1.4.1).
Are my images uploaded?
No. Images are processed with the Canvas API inside your browser and never leave your device.