Color Blindness Simulator

Enter any color and see how it appears with protanopia, deuteranopia, tritanopia, and achromatopsia.

Last reviewed: April 2026
Reviewed by , software engineer · last updated April 2026

New to this tool? Click here for instructions

Quick palette test:

Enter a hex color above to simulate color blindness.

How to Use the Color Blindness Simulator

The Color Blindness Simulator is a free online tool that allows you to simulate how colors appear to people with different types of color vision deficiency. To use the simulator, simply enter a hex code or RGB value of the color you want to simulate. The tool will instantly show how your color appears under all four major types of color vision deficiency: protanopia, deuteranopia, tritanopia, and achromatopsia.

When to Use the Tool in Real Workflows

The Color Blindness Simulator is particularly useful when designing user interfaces, creating charts, and developing any visual content that relies on color coding. It helps ensure that your designs are accessible to users with color vision deficiency, which affects approximately 8% of males and 0.5% of females worldwide.

How It Works

The Color Blindness Simulator uses mathematically derived color transformation matrices to simulate how colors appear to people with different types of color vision deficiency. The simulator supports protanopia, deuteranopia, tritanopia, and achromatopsia. For protanopia and deuteranopia, the simulator uses the Vienot (1999) model, while the tritanopia simulation uses an approximation of the Brettel (1997) dichromatic model. Achromatopsia is simulated using standard luminance weighting (ITU-R BT.601).

Tips, Edge Cases, or Limitations

When using the Color Blindness Simulator, it's important to remember that it is a client-side tool and does not require an internet connection. However, it may not be 100% accurate in all cases, as it is based on mathematical models and may not perfectly simulate the experience of a person with color vision deficiency.

Frequently Asked Questions

The most common types of color blindness are deuteranopia (green-blind), affecting about 5% of males, and protanopia (red-blind), affecting about 1% of males. Tritanopia (blue-blind) is rare, and achromatopsia (total color blindness) is extremely rare.
The simulator uses the Vienot (1999) model for protanopia and deuteranopia, and an approximation of the Brettel (1997) dichromatic model for tritanopia. Achromatopsia is simulated using standard luminance weighting (ITU-R BT.601).
Color blindness accessibility is important because it ensures that visual content is understandable to everyone, including those with color vision deficiency. This can improve user experience and reduce the likelihood of errors or misunderstandings.
Protanopia is a type of color blindness where red is perceived as black or very dark shades of red. Deuteranopia is a type of color blindness where green is perceived as brown or very dark shades of green.
To make your design accessible to color-blind users, consider using color contrast ratios that meet WCAG AA and AAA thresholds, avoid using color as the only means of conveying information, and provide alternative text or labels for images.