Vision Simulator
See your palette through different eyes. Design more inclusive color systems.
Original Palette
Click a swatch to change its color
Simulated View
Click a hex to copy it
What Is Color Blindness?
Color blindness (color vision deficiency) is the reduced ability to distinguish certain colors. It affects approximately 1 in 12 men and 1 in 200 women worldwide (around 300 million people globally). In most cases it is inherited and caused by an absence or malfunction of one or more of the three types of cone cells in the retina that detect red, green, and blue light.
This simulator applies the Machado, Oliveira, and Velho (2009) transformation matrices to your palette, the same scientifically validated model used by professional accessibility tools. The results show which colors become indistinguishable under each condition, helping you design inclusive interfaces from the start.
Vision Types Simulated
Protanopia: No Red Cones
The L (long wavelength) cones that detect red are absent. Reds and greens merge into browns and yellows. Affects ~1% of men. Traffic lights relying solely on red vs. green position are difficult to interpret.
Deuteranopia: No Green Cones
The M (medium wavelength) cones that detect green are absent. The most common inherited color vision deficiency, affecting ~6% of men. Red and green are again confused, but the luminance perception is less affected than in protanopia.
Tritanopia: No Blue Cones
The S (short wavelength) cones that detect blue are absent. Blue and yellow are confused; blue appears green and yellow appears violet or light grey. Rare, affecting under 0.01% of the population equally across sexes. More commonly acquired than inherited.
Achromatopsia: Monochromacy
Complete absence of color vision; the world is perceived in shades of grey. Caused by the total absence or dysfunction of cone cells, leaving only rod cells. Very rare (~1 in 30,000), often accompanied by light sensitivity and reduced visual acuity.
How the Simulation Works
This tool uses the perceptually accurate simulation model published by Machado, Oliveira, and Velho (2009), which is the same method used by professional accessibility tools and most modern color blindness simulators. Unlike older approximations that simply swap color channels, this model applies empirically-derived 3x3 transformation matrices that closely match the actual cone response functions of affected individuals.
The pipeline for each pixel is: linearize the sRGB values (remove gamma encoding), multiply by the transformation matrix for the selected condition, then re-apply gamma encoding to get the simulated display color. This ensures the simulation is physically meaningful rather than a visual approximation.
The Transformation Matrix
Each condition (protanopia, deuteranopia, tritanopia) has a unique 3x3 matrix that remaps R, G, B channels to simulate the missing or shifted cone response. The achromatopsia simulation uses standard luminance weights (0.299 R + 0.587 G + 0.114 B) applied to all three channels.
Simulation vs. Daltonization
This tool simulates how colors appear to someone with CVD so that sighted designers can empathize. "Daltonization" is the opposite: it shifts colors in an image to make it more distinguishable for color-blind viewers. These are inverse operations; this tool only implements simulation.
Designing for Color Vision Deficiency
- Never use red/green alone - the most common error. Pair color with icons, patterns, or text labels to communicate status.
- Use lightness contrast - even where hue is confused, large lightness differences remain distinguishable. Prioritize luminance differences in data visualizations.
- Choose blue/orange palettes for charts - these hues remain distinguishable across all three common dichromatic deficiencies.
- Simulate early, not late - run the simulator on your palette before building the UI, not after. Retrofitting accessible colors is far more expensive than choosing them from the start.