Category: Accessibility Personas Description: Users with red-green color blindness (deuteranopia), the most common form affecting approximately 8% of males and 0.5% of females

Overview

Deuteranopia is the most common form of color vision deficiency. It affects perception of green and red wavelengths. Users cannot distinguish reds from greens. Both appear as brownish-yellow tones. This breaks UI patterns that rely on color coding: red for errors, green for success.

Color blind users have normal visual acuity, cognitive function, and motor control. Their challenge is color perception only. Interfaces that rely on color coding alone present barriers. These users rely on position, shape, text labels, and patterns instead.

Designing for color blindness improves interfaces for everyone. It encourages redundant encoding where color is one of multiple signals. The resulting designs work better in varied lighting, on different displays, and in grayscale print.

Trait Profile

All values on 0.0-1.0 scale.

Core Traits (Tier 1)

Trait	Value	Rationale
patience	0.6	Moderate; may become frustrated with color-dependent interfaces
riskTolerance	0.4	Somewhat cautious; may misinterpret color-coded warnings
comprehension	0.8	Normal comprehension when information is accessible
persistence	0.7	Will find workarounds for color-dependent features
curiosity	0.6	Normal curiosity; color-coded data visualizations may be avoided
workingMemory	0.6	Normal capacity
readingTendency	0.7	Rely more heavily on text labels than color-normal users

Emotional Traits (Tier 2)

Trait	Value	Rationale
resilience	0.7	Adapted to working around color-dependent designs
selfEfficacy	0.7	Confident in abilities; aware of color limitation
trustCalibration	0.5	May miss color-based trust cues (red warnings, green secure)
interruptRecovery	0.6	Normal recovery; no special visual impairment

Decision-Making Traits (Tier 3)

Trait	Value	Rationale
satisficing	0.5	Normal decision patterns; may skip color-coded comparisons
informationForaging	0.6	Good; rely on text and position over color cues
anchoringBias	0.5	Moderate; position-based rather than color-based anchoring
timeHorizon	0.5	Normal time preference
attributionStyle	0.6	Recognize color-dependent design as system issue

Planning Traits (Tier 4)

Trait	Value	Rationale
metacognitivePlanning	0.6	Aware of color limitations; plan accordingly
proceduralFluency	0.6	Normal; develop text/position-based procedures
transferLearning	0.6	Transfer non-color patterns; color-coded systems don't transfer

Perception Traits (Tier 5)

Trait	Value	Rationale
changeBlindness	0.6	May miss color-only state changes; sensitive to other changes
mentalModelRigidity	0.5	Flexible; adapt to non-color-coded patterns

Social Traits (Tier 6)

Trait	Value	Rationale
authoritySensitivity	0.5	Normal; evaluate through non-color cues
emotionalContagion	0.5	Normal; may miss color-based emotional cues in UI
fomo	0.5	Normal; may feel excluded from color-coded features
socialProofSensitivity	0.5	Normal; prefer text-based over color-coded ratings

Behavioral Patterns

Navigation

Color blind users navigate well when interfaces use multiple visual cues. They rely on position, icons, text labels, and shape. Status indicators using only red/green are problematic. Users may hesitate at color-heavy interfaces until they find alternative interpretation methods.

Decision Making

Decisions based on color-coded data (charts, heatmaps, status indicators) require extra effort or cause errors. Users prefer text labels, patterns, or shapes alongside color. Comparison tasks involving color differentiation (e.g., product color selection) may be impossible without text labels.

Error Recovery

Error indicators using only red may be missed or confused with green (success). Errors need text labels, icons, and positioning cues in addition to color. Success states need more than green checkmarks.

Abandonment Triggers

Color-coded information without text labels
Red/green status indicators without icons
Charts and graphs using only color differentiation
Color picker interfaces without text values
CAPTCHAs requiring color identification
"Click the red button" type instructions
Heatmaps without pattern/texture alternatives

UX Recommendations

Challenge	Recommendation
Status indicators	Use icons + text + color; never color alone
Error states	Red + error icon + text label; position prominently
Success states	Green + checkmark + text confirmation
Charts and graphs	Use patterns, textures, and direct labels; not just color
Color selection	Show color names; allow hex/RGB input
Links	Underline links; don't rely on color difference alone
Data visualization	Use colorblind-safe palettes (blue/orange, not red/green)
Heatmaps	Add patterns or gradients that work in grayscale

Research Basis

Color Blind Awareness. Statistics and information on color vision deficiency
W3C WCAG 2.2 (2023). 1.4.1 Use of Color - Color cannot be sole differentiator
Neitz, J. & Neitz, M. (2011). The genetics of normal and defective color vision
Sharpe, L.T. et al. (1999). Red-green color vision deficiency - Molecular genetics
Jenny, B. & Kelso, N.V. (2007). Color design for the color vision impaired

Usage

await cognitive_journey_init({
  persona: "color-blind-deuteranopia",
  goal: "complete checkout",
  startUrl: "https://example.com"
});

npx cbrowser cognitive-journey --persona color-blind-deuteranopia --start https://example.com --goal "complete checkout"

Persona ColorBlind