What is color blindness and how common is it?

Color blindness (color vision deficiency) is the decreased ability to see colors or differences between colors. It affects about 8% of males and 0.5% of females worldwide (roughly 300 million people), making it crucial to design with accessibility in mind.

How do I simulate color blindness online?

Enter a color, upload an image, or input a color palette. The tool shows how it appears to people with different types of color vision deficiency: protanopia, deuteranopia, tritanopia, and their milder forms. Test single colors, palettes, or full images.

What types of color blindness does this simulator support?

This tool simulates 7 types: Protanopia (red-blind), Deuteranopia (green-blind), Tritanopia (blue-blind), Achromatopsia (total color blindness), and milder forms - Protanomaly (red-weak), Deuteranomaly (green-weak), and Tritanomaly (blue-weak).

What is the difference between -opia and -omaly color blindness?

-opia means complete absence of a cone type (more severe). -omaly means reduced sensitivity (milder form). For example, protanopia is complete red-blindness while protanomaly is red-weakness. -omaly types are more common.

Which type of color blindness is most common?

Deuteranomaly (green-weak) is most common, affecting about 5% of males. Red-green color blindness overall (protanopia, protanomaly, deuteranopia, deuteranomaly) affects about 8% of males. Testing for these should be a priority.

How does the palette testing feature work?

The palette tester analyzes all color pairs in your palette across all 7 vision types. It calculates a distinguishability score and identifies problematic pairs that may look too similar to users with color vision deficiencies.

What does the accessibility score mean?

The accessibility score (0-100%) indicates what percentage of color pair comparisons remain distinguishable across all vision types. Above 80% is good, 60-80% needs improvement, below 60% indicates significant accessibility issues.

How does the contrast checker work with color blindness?

The contrast checker simulates your text/background colors for each vision type and calculates the WCAG contrast ratio. This ensures your text remains readable for users with any type of color vision deficiency.

What WCAG contrast levels should I aim for?

WCAG AA requires 4.5:1 for normal text and 3:1 for large text. WCAG AAA requires 7:1 for normal text and 4.5:1 for large text. Aim for AA compliance at minimum, AAA for critical content. Check contrast for all vision types.

How can I design for color blindness accessibility?

Use high contrast, avoid red-green combinations, add patterns or labels to color-coded elements, never rely solely on color to convey information, use icons alongside color indicators, and test your designs with this simulator.

Can I test images with this color blindness simulator?

Yes! Upload any image (PNG, JPG, GIF, WebP) to see a side-by-side comparison of how it appears to users with different types of color vision deficiency. You can also download the simulated versions.

How accurate is this color blindness simulation?

This tool uses scientifically-derived color transformation matrices that closely approximate how colors appear to people with color vision deficiencies. While individual experiences may vary, these simulations are widely accepted for accessibility testing.

What colors should I avoid using together?

Avoid red-green combinations (problematic for ~8% of males), blue-yellow combinations (problematic for tritanopia), and any colors that become similar when desaturated. Use the palette tester to identify specific problematic pairs in your design.

What is achromatopsia (total color blindness)?

Achromatopsia is complete color blindness where a person sees only in grayscale. It's rare (1 in 30,000 people) but important to consider. Designs that work in grayscale work for everyone. Test by converting your design to grayscale.

Is my color data private when using this simulator?

Yes! All color blindness simulations happen 100% in your browser using JavaScript. No data is sent to any server, stored, or logged. Your colors and images remain completely private on your device.

What is color blindness and how common is it?

Color blindness (color vision deficiency) is the decreased ability to see colors or differences between colors. It affects about 8% of males and 0.5% of females worldwide (roughly 300 million people), making it crucial to design with accessibility in mind.

How do I simulate color blindness online?

Enter a color, upload an image, or input a color palette. The tool shows how it appears to people with different types of color vision deficiency: protanopia, deuteranopia, tritanopia, and their milder forms. Test single colors, palettes, or full images.

What types of color blindness does this simulator support?

This tool simulates 7 types: Protanopia (red-blind), Deuteranopia (green-blind), Tritanopia (blue-blind), Achromatopsia (total color blindness), and milder forms - Protanomaly (red-weak), Deuteranomaly (green-weak), and Tritanomaly (blue-weak).

What is the difference between -opia and -omaly color blindness?

-opia means complete absence of a cone type (more severe). -omaly means reduced sensitivity (milder form). For example, protanopia is complete red-blindness while protanomaly is red-weakness. -omaly types are more common.

Which type of color blindness is most common?

Deuteranomaly (green-weak) is most common, affecting about 5% of males. Red-green color blindness overall (protanopia, protanomaly, deuteranopia, deuteranomaly) affects about 8% of males. Testing for these should be a priority.

How does the palette testing feature work?

The palette tester analyzes all color pairs in your palette across all 7 vision types. It calculates a distinguishability score and identifies problematic pairs that may look too similar to users with color vision deficiencies.

What does the accessibility score mean?

The accessibility score (0-100%) indicates what percentage of color pair comparisons remain distinguishable across all vision types. Above 80% is good, 60-80% needs improvement, below 60% indicates significant accessibility issues.

How does the contrast checker work with color blindness?

The contrast checker simulates your text/background colors for each vision type and calculates the WCAG contrast ratio. This ensures your text remains readable for users with any type of color vision deficiency.

What WCAG contrast levels should I aim for?

WCAG AA requires 4.5:1 for normal text and 3:1 for large text. WCAG AAA requires 7:1 for normal text and 4.5:1 for large text. Aim for AA compliance at minimum, AAA for critical content. Check contrast for all vision types.

How can I design for color blindness accessibility?

Use high contrast, avoid red-green combinations, add patterns or labels to color-coded elements, never rely solely on color to convey information, use icons alongside color indicators, and test your designs with this simulator.

Can I test images with this color blindness simulator?

Yes! Upload any image (PNG, JPG, GIF, WebP) to see a side-by-side comparison of how it appears to users with different types of color vision deficiency. You can also download the simulated versions.

How accurate is this color blindness simulation?

This tool uses scientifically-derived color transformation matrices that closely approximate how colors appear to people with color vision deficiencies. While individual experiences may vary, these simulations are widely accepted for accessibility testing.

What colors should I avoid using together?

Avoid red-green combinations (problematic for ~8% of males), blue-yellow combinations (problematic for tritanopia), and any colors that become similar when desaturated. Use the palette tester to identify specific problematic pairs in your design.

What is achromatopsia (total color blindness)?

Achromatopsia is complete color blindness where a person sees only in grayscale. It's rare (1 in 30,000 people) but important to consider. Designs that work in grayscale work for everyone. Test by converting your design to grayscale.

Is my color data private when using this simulator?

Yes! All color blindness simulations happen 100% in your browser using JavaScript. No data is sent to any server, stored, or logged. Your colors and images remain completely private on your device.

Color Blindness Simulator

advanced

Advanced color blindness simulator with image processing, palette testing, and WCAG contrast checking for all vision types including protanopia, deuteranopia, and tritanopia.

Color Toolscolor blindnessaccessibilitysimulationprotanopia

100% Private - Runs Locally

How to Use

1Test single colors across all vision types
2Analyze color palettes for accessibility issues
3Check text/background contrast for each vision type
4Upload images to see how they appear to color blind users

Examples

Red with Protanopia

Input

#FF0000 (Red)

Output

#918E00 (Appears olive/brown)

Green with Deuteranopia

Input

#00FF00 (Green)

Output

#D4B200 (Appears yellow/brown)

Blue with Tritanopia

Input

#0000FF (Blue)

Output

#007A7A (Appears teal)

Traffic Light Palette Test

Input

Red #FF0000, Yellow #FFFF00, Green #00FF00

Output

Score: 45% - Red and green are indistinguishable for deuteranopia

Accessible Palette

Input

Blue #2563EB, Orange #F97316, Purple #9333EA, Teal #14B8A6

Output

Score: 92% - Good contrast across all vision types

Text Contrast Check

Input

Text #1E293B on Background #FFFFFF

Output

Passes WCAG AA/AAA for all vision types (ratio 12.63:1)

Image Simulation

Input

Upload any image (PNG, JPG, GIF, WebP)

Output

Side-by-side comparison showing how the image appears to each vision type

Frequently Asked Questions

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