Color Vision Deficiency & Palette Accessibility Tester

Human color perception is driven by three retinal cone photopigments sensitive to specific light wavelengths: L-cones (Long / Red, ~560 nm), M-cones (Medium / Green, ~530 nm), and S-cones (Short / Blue, ~420 nm). Congenital color vision deficiencies result from the absence or functional anomaly of these cone types:

• Protanopia (L-Cone Deficiency): Red wavelengths appear dark brown or charcoal; red-green distinctions are lost (affects ~1% of males).
• Deuteranopia (M-Cone Deficiency): Green and red wavelengths collapse along similar yellowish-tan lines (the most common CVD form, affecting ~5% of males).
• Tritanopia (S-Cone Deficiency): Blue and yellow distinctions are lost; blues look greenish and yellows look pinkish (rare, affects under 0.1% of people).
• Achromatopsia (Rod Monochromacy): Complete absence of cone photopigments; vision is mediated solely by rod cells in grayscale luminance.

The simulator uses Brettel-Viénot-Mollon transformation algorithms to project input sRGB coordinates onto simulated dichromatic planes. By calculating Euclidean color distance ($\Delta E$) between simulated pairs, the tool automatically warns you whenever two colors in your palette fall below the safe threshold of 42, alerting you to potential WCAG 1.4.1 (Use of Color) accessibility violations.