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Colour blindness simulator.
See your palette as roughly 300 million people do — and find out which of your colours stop being distinguishable from each other.
How this works
This is a settled colour-space transform, not a guess: colours are converted to LMS cone-response space, the missing cone type is projected out, and the result is converted back. No AI, no server, nothing uploaded. The useful part is not the pretty swatches — it is the collision list at the bottom, which tells you which pairs collapse into each other.
One hex colour per line, or separated by spaces or commas. Paste your brand palette, or the colours you use for status, errors and success.
Simulation approximates dichromacy — the complete absence of one cone type. Most people with colour vision deficiency have anomalous trichromacy, a partial shift, and see something between these swatches and normal vision. Treat this as a design check, not a description of any individual's experience.
Find out what's broken.
Then actually fix it.
One URL. Nine seconds. No account, no card, no call.