Color blindness simulator
See how a photo, chart, design or palette looks with different kinds of color blindness. Images are processed in your browser and never uploaded. For palettes, the simulator flags colors that become hard to tell apart.
Simulate color blindness
Types of color blindness
| Type | What happens | How common |
|---|---|---|
| Protanopia | Red cones missing: reds look dark, red and green are confused | About 1% of men |
| Deuteranopia | Green cones missing: red and green are confused | About 1% of men |
| Deuteranomaly | Green cones shifted: the most common form, milder confusion | About 5% of men |
| Tritanopia | Blue cones missing: blue and green, and yellow and pink, are confused | Rare |
| Achromatopsia | No working cones: everything is seen in shades of gray | Very rare |
In total about 1 in 12 men and 1 in 200 women have some form of color vision deficiency, most often red-green. That is why color should never be the only way to show information.
How the simulation works
The simulator uses the physiologically based model by Machado, Oliveira and Fernandes (2009), which transforms colors in linear RGB to show how they appear with a given cone deficiency. Achromatopsia is shown as luminance only. It is a good approximation for design checks, not a diagnosis: individual vision varies.
How to check a design or palette
- Enter your palette colors, or export a screenshot of the design and choose it as an image.
- Look at the deuteranopia and protanopia views first: red-green problems are the most common.
- Fix any pair the simulator flags by changing lightness, not just hue.
- Check the achromatopsia view: if two colors look the same gray, they also fail for many low-vision users.
| Colors that often clash | For whom |
|---|---|
| Red and green | Protanopia, deuteranopia |
| Green and brown | Protanopia, deuteranopia |
| Blue and purple | Protanopia, deuteranopia |
| Blue and green | Tritanopia |
| Yellow and pink | Tritanopia |
Designing for color blindness
- Do not rely on color alone: add labels, icons, patterns or position.
- Avoid red and green as the only difference between two states.
- Make colors differ in lightness as well as hue, and check contrast in the contrast checker.
- For charts, use a color-blind-safe palette from the chart color tool, or browse colorblind-friendly palettes.
Frequently asked questions
How can I see what color blind people see?
Use the simulator above: choose an image or enter colors to see them with each type of color blindness.
What is the most common type of color blindness?
Red-green color blindness, mostly deuteranomaly, which affects about 5% of men.
Are my images uploaded?
No. The simulation runs entirely in your browser; the image never leaves your device.
Is this a color blindness test?
No. It simulates color vision deficiency for design checks. A test needs proper conditions and is best done by an eye care professional.