ColorBlindnessTypes [fact] v1.0.0

Approximately 8% of men and 0.5% of women have a form of color vision deficiency — most commonly red-green (deuteranopia / protanopia). The implication for design is that color must never be the sole channel encoding meaning.

Roughly 8% of men of Northern European descent and 0.5% of women have a color vision deficiency — broken into protanopia / protanomaly (red-perception, ~1% men), deuteranopia / deuteranomaly (green-perception, ~6% men, the most common), tritanopia / tritanomaly (blue-yellow, < 0.01% — extremely rare), and the rare achromatopsia (full color absence) — meaning red-green encoding is the largest accessibility risk and color must always be paired with a non-color channel (icon, label, pattern, position).

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Confidence

proven

Applies To

• status indicators (success / warning / error must include icon + text)
• data viz palettes (avoid red-green diverging without secondary cue)
• form validation (don't rely on red border alone)
• category encoding (pair color with shape / pattern / label)

Quantitative

• Male Prevalence Northern European: ~8%
• Female Prevalence: ~0.5%
• Deuteranopia Share: ~6% of men (most common)
• Protanopia Share: ~1% of men
• Tritanopia Share: < 0.01% (rare)
• Achromatopsia Share: ~0.003% (very rare, full color blindness)

Counter Conditions

• Prevalence varies by ethnic background — lower in East Asian populations (5% men), higher in Northern European (8%).
• Severity ranges from anomaly (reduced perception) to full -opia (absent perception) — most affected users have anomaly, not full absence.
• Color-blind-safe palettes (Viridis, ColorBrewer Set1 with shape redundancy, IBM Carbon CB-safe) handle red-green and blue-yellow simultaneously.

ColorBlindnessTypes [fact] v1.0.0

Approximately 8% of men and 0.5% of women have a form of color vision deficiency — most commonly red-green (deuteranopia / protanopia). The implication for design is that color must never be the sole channel encoding meaning.

Roughly 8% of men of Northern European descent and 0.5% of women have a color vision deficiency — broken into protanopia / protanomaly (red-perception, ~1% men), deuteranopia / deuteranomaly (green-perception, ~6% men, the most common), tritanopia / tritanomaly (blue-yellow, < 0.01% — extremely rare), and the rare achromatopsia (full color absence) — meaning red-green encoding is the largest accessibility risk and color must always be paired with a non-color channel (icon, label, pattern, position).

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Confidence

proven

Applies To

• status indicators (success / warning / error must include icon + text)
• data viz palettes (avoid red-green diverging without secondary cue)
• form validation (don't rely on red border alone)
• category encoding (pair color with shape / pattern / label)

Quantitative

• Male Prevalence Northern European: ~8%
• Female Prevalence: ~0.5%
• Deuteranopia Share: ~6% of men (most common)
• Protanopia Share: ~1% of men
• Tritanopia Share: < 0.01% (rare)
• Achromatopsia Share: ~0.003% (very rare, full color blindness)

Counter Conditions

• Prevalence varies by ethnic background — lower in East Asian populations (5% men), higher in Northern European (8%).
• Severity ranges from anomaly (reduced perception) to full -opia (absent perception) — most affected users have anomaly, not full absence.
• Color-blind-safe palettes (Viridis, ColorBrewer Set1 with shape redundancy, IBM Carbon CB-safe) handle red-green and blue-yellow simultaneously.

Sources

Relations

related: [@community/fact-hue-temperature-bias, @community/fact-contrast-ratio-aa-vs-aaa, @community/constraint-accessibility-aa-minimum]

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Confidence

proven

Source

• National Eye Institute (NIH) — color blindness prevalence statistics
• Birch, J., 'Worldwide prevalence of red-green color deficiency', Journal of the Optical Society of America A (2012)
• WCAG 2.2 SC 1.4.1 Use of Color — meaning must not be conveyed by color alone
• Pilestone / Coblis simulator tools

Applies To

• status indicators (success / warning / error must include icon + text)
• data viz palettes (avoid red-green diverging without secondary cue)
• form validation (don't rely on red border alone)
• category encoding (pair color with shape / pattern / label)

Quantitative

• Male Prevalence Northern European: ~8%
• Female Prevalence: ~0.5%
• Deuteranopia Share: ~6% of men (most common)
• Protanopia Share: ~1% of men
• Tritanopia Share: < 0.01% (rare)
• Achromatopsia Share: ~0.003% (very rare, full color blindness)

Counter Conditions

• Prevalence varies by ethnic background — lower in East Asian populations (5% men), higher in Northern European (8%).
• Severity ranges from anomaly (reduced perception) to full -opia (absent perception) — most affected users have anomaly, not full absence.
• Color-blind-safe palettes (Viridis, ColorBrewer Set1 with shape redundancy, IBM Carbon CB-safe) handle red-green and blue-yellow simultaneously.