Color Blindness Simulator – Free Online Color Blind Filter for Images

How does your painting, design, or photo look to someone with color blindness? Our free color blindness simulator shows your image through the eyes of people with red-green, blue-yellow, and complete color blindness, side by side or with a comparison slider. A palette checker flags color pairs that become hard to tell apart. Everything runs in your browser, so your image is never uploaded.

How to Use the Color Blindness Simulator

Checking an image takes only a few seconds:

1. Add your image. Click “Upload image”, drag a file onto the picture area, press Ctrl+V (Cmd+V on a Mac) to paste a screenshot, or paste an image link (some websites block this; if so, save the image and upload it). On a phone or tablet, “Take photo” opens your camera. You can also start with one of four sample paintings.
2. Compare all types at once. The “All types” view shows the original next to protanopia, deuteranopia, tritanopia, and achromatopsia.
3. Open one type large. Click “View large” or switch to “Single type”. Drag across the image or use the “Compare” slider to move the divider between the original (left) and the simulation (right).
4. Set the severity. Move the severity slider from 100% (complete color blindness) down to milder forms. The same setting is used by the palette checker.
5. Save or print your result. In the “All types” view, “Download PNG” and “Print” give you all five versions on one labeled sheet. In the single view, “Download PNG” saves the simulated image, “Download comparison” saves the original and the simulation side by side, and “Print” prints that comparison.

The Types of Color Vision Deficiency You Can Simulate

Normal color vision relies on three types of cone cells, sensitive to long (red), medium (green), and short (blue) wavelengths. Color vision deficiency happens when one type is missing or works differently:

Names ending in “-opia” describe complete loss of one cone type (dichromacy). Names ending in “-omaly” describe a milder form in which the cone is present but its sensitivity is shifted (anomalous trichromacy). In the simulator, 100% severity shows the “-opia” form, lower values show the “-omaly” form, and 0% shows normal vision.

How Common Is Color Blindness?

Red-green color blindness is by far the most common form. According to MedlinePlus Genetics from the U.S. National Library of Medicine, it affects about 1 in 12 men and 1 in 200 women with Northern European ancestry, or roughly 8% of men and 0.5% of women. It is less common in almost all other populations studied. Men are affected much more often because the genes for the red and green cones sit on the X chromosome.

Blue-yellow color vision defects are rare and occur in fewer than 1 in 10,000 people worldwide, affecting men and women equally. Achromatopsia, a partial or total lack of color vision, affects about 1 in 30,000 people. The National Eye Institute names deuteranomaly as the most common type of red-green color vision deficiency.

Compare the Colors of a Single Pixel

Click or tap any spot in the image. The “Pixel colors” panel shows the HEX code of the original pixel and of the same pixel with each type, plus the color difference (ΔE) between them. On a computer, the panel follows your pointer until you click, and the arrow keys move the marker (Shift moves ten pixels). “Copy values” copies all codes, and “Add to palette checker” sends the original color to the palette checker.

Check Your Color Palette for Color Blindness

Below the image, the palette checker tests up to eight colors at once. Choose each color with the color picker or type its HEX code. You can also paste a list of up to eight HEX codes (with or without the # sign) or rgb() values to replace the palette, or click “Use colors from image” to load the six dominant colors of your current image.

The tool shows your palette with normal vision and with each of the four types. For every pair, it calculates the CIEDE2000 color difference (ΔE), a standard formula for how different two colors look. Pairs below your threshold (5, 10, 15, or 20) are outlined in red and listed by number. We recommend 10 as a practical rule of thumb, not an official standard. Choose a higher value for small elements such as thin lines or chart dots.

Copy the result as a text report, download it as a PNG, or print it. For new color ideas, try our color palette generator.

How the Simulation Works

Each pixel is converted from sRGB to linear RGB (removing the gamma curve), run through a model of the affected cones, and converted back:

• Protan and deutan types use the physiologically based model by Machado, Oliveira, and Fernandes, published in 2009. Its authors provide matrices for every severity step of 10%, and the tool interpolates between the two nearest steps, as the authors suggest.
• Tritan types use the dichromat model by Brettel, Viénot, and Mollon from 1997, which independent comparisons of simulation methods recommend over the 2009 model for blue-yellow deficiency. Milder severities are blended with the original colors.
• Achromatopsia is shown as the relative luminance of each color, the same brightness measure used in web accessibility guidelines.

Images larger than 2,000 pixels on their longest side are scaled down to 2,000 pixels for the simulation, and the single-image download uses this size. The tool does not include a separate blue cone monochromacy view. This very rare condition affects about 1 in 100,000 people, and its color perception is not well described by a simple filter. The achromatopsia view is the closest approximation.

Keep in mind that any simulation is an approximation. Two people with the same diagnosis can see colors differently, many have a mild form, and your screen settings affect what you see. Achromatopsia also causes light sensitivity and reduced sharpness, which the tool does not show.

Why Color Blindness Matters for Artists

Many classic color pairings rely on red and green. These are complementary colors that look vivid together on the color wheel, but for a large part of the audience, they can lose their contrast. Load “Monet: Poppies” in the tool to see an example. In Monet’s Wild Poppies Near Argenteuil, the bright red flowers stand out against the green field, but in the protanopia view they turn dark olive and lose most of their contrast with the meadow; only their darker value still sets them apart. Learn more about mixing red and green.

The achromatopsia view is also a quick value check. Artists often squint or photograph their work in black and white to judge light and dark. If your focal point disappears in gray, it relies on hue alone. Our guides to value in art and contrast in art explain why this matters.

Some artists have color vision deficiency themselves. The French printmaker Charles Meryon (1821 to 1868) took painting lessons but turned to etching after realizing that his color blindness ruled out a career as a painter, and he became famous for his etchings of Paris. Claims that Vincent van Gogh was color blind rest mainly on modern simulations of his paintings, not on medical evidence, and remain speculation.

Tips for Color-Blind-Friendly Art and Design

• Use lightness differences. Make one color clearly lighter or darker than the other. Differences in lightness hold up much better than differences in hue.
• Do not rely on red and green alone. Blue and orange are a safer pair, for example, to mark good and bad.
• Add a second cue. Labels, icons, patterns, textures, and outlines mean nobody has to rely on color alone.
• Check the whole palette. A pair that works on its own may clash with a third color. Run all your colors through the palette checker.

Who Uses a Color Blindness Simulator?

• Painters and illustrators check whether a focal point still stands out.
• Designers test logos, buttons, charts, and maps before they go live.
• Teachers make sure worksheets and slides work for every student.
• Game and app developers check team colors and status icons.

Your Images Stay Private

The simulator works entirely in your browser. Your image is not uploaded or stored, so you can safely check unpublished artwork and client files. The only thing the tool remembers is your palette, which is saved in your own browser for your next visit. The sample paintings load from Wikimedia Commons.

More Free Art Tools

All our tools are free, run in your browser, and need no account. See them all on the free art tools page.

• Image color picker: find the exact colors in any photo or painting.
• Color name finder: get the name of any HEX, RGB, or photo color.
• Color wheel: find complementary, triadic, and analogous colors.
• Color mixer: mix paint or screen colors and find paint recipes.
• Color palette generator: create matching color schemes or a palette from an image.
• Photo to sketch: turn a photo into a pencil sketch or line art.
• Photo to coloring page: turn any picture into a printable coloring page.
• Image to pixel art: convert an image into editable pixel art.
• Notan generator: plan light and dark shapes with a two- or three-value study.
• Art grid tool: put a drawing grid over any photo.
• Golden ratio overlay: check your composition with a golden spiral and rule of thirds.
• Perspective grid generator: print one-, two-, and three-point perspective grids.
• Paint by number generator: turn a photo into a printable paint by number template.
• Art pricing calculator: find a fair price for your paintings and prints.
• Art prompt generator: get random ideas for drawing and painting.
• Random character generator: create an original character with traits and a palette.

Frequently Asked Questions

What Does Color Blindness Look Like?

It depends on the type. With red-green color blindness, reds, greens, oranges, and browns look similar. With blue-yellow color blindness, blue and green or yellow and pink are hard to tell apart. Upload any image above to see all types side by side.

What Is the Most Common Type of Color Blindness?

Red-green color blindness is the most common form, and deuteranomaly, a reduced sensitivity of the green cones, is its most common type. It affects about 1 in 12 men and 1 in 200 women with Northern European ancestry.

How Accurate Is a Color Blindness Simulator?

Good simulators are based on models of how the cones respond to light, so they give a useful approximation. They cannot show exactly what one person sees, because color vision differs between people. This tool uses the Machado (2009) and Brettel (1997) models.

What Is the Difference Between Protanopia and Deuteranopia?

Both are forms of red-green color blindness. In protanopia, the red-sensitive cones are missing, so reds also look darker. In deuteranopia, the green-sensitive cones are missing, and reds keep more of their brightness. The confused colors are similar, which is why the two types are often grouped together.

Can Women Be Color Blind?

Yes, but red-green color blindness is much rarer in women, at about 1 in 200 among people with Northern European ancestry. Because the genes involved sit on the X chromosome, a woman needs the changed gene on both X chromosomes to be affected. Blue-yellow color blindness affects men and women equally.

Which Colors Are Best for Color Blind People?

Combinations with a clear difference in lightness work best, such as dark blue with light orange or yellow. Avoid using red and green, or blue and purple, as the only difference between important elements, and test your colors with the palette checker.

Is the Color Blindness Simulator Free?

Yes. The simulator is free, needs no sign-up, and adds no watermark. Your images are processed in your browser and never uploaded.