How does the tool know a palette is safe?

It simulates protanopia, deuteranopia, and tritanopia on every color, then measures the perceptual distance between each pair in CIELAB. If any pair becomes too close under any simulation, the palette is rejected and a new one is tried.

Which types of color blindness are covered?

The three dichromacy types — protanopia (no red cones), deuteranopia (no green cones), and tritanopia (no blue cones). These cover the most common and most severe forms of color vision deficiency.

Should I rely on color alone?

No. Even a safe palette should be paired with another channel such as labels, patterns, or shapes. Color is a helpful redundant cue, not the only one.

Why do some colors never appear?

Saturated reds and greens collapse together under red-green deficiency, so the generator naturally avoids placing two such colors in the same palette. You will see more blues, oranges, and varied lightness instead.

Color-Blind Safe Palette Generator

Palettes that work for every kind of color vision

Roughly one in twelve men has some form of color vision deficiency (CVD). A palette that looks fine to you might turn a green and an orange series into the same muddy color for them. This tool generates palettes and then verifies each one by simulating the three dichromacy types and rejecting any pair of colors that becomes indistinguishable.

How it works

For each candidate palette the tool runs three steps per color:

Simulate CVD. Colors are converted to the LMS cone space and projected through the Brettel/Viénot dichromat matrices for protanopia, deuteranopia, and tritanopia.
Convert to CIELAB. Both the simulated colors are converted to L*a*b*, a perceptually-uniform space where Euclidean distance approximates how different two colors look.
Check every pair. It measures the CIE76 deltaE between each pair after each simulation. If the smallest distance across all pairs and all simulations stays above a safety threshold, the palette passes.

It also enforces a minimum lightness spread so colors differ in brightness too, which helps grayscale printing and the achromatic case.

Tips and notes

Always add a second cue. Labels, dashes, and markers make a chart readable even for someone who turns off color entirely.
The simulation is the standard dichromat model, so it represents the severe end of each deficiency — passing here means anomalous (milder) cases are safe too.
Smaller palettes are easier to keep safe. If you need many series, consider grouping or faceting instead of cramming colors together.