# Accessibility Examples
This section demonstrates accessibility tools that help ensure colors meet WCAG standards and are usable by people with color vision deficiencies.
## Available Tools
- **check_contrast** - Verify WCAG contrast compliance
- **simulate_colorblindness** - Show how colors appear to users with color vision deficiencies
- **optimize_for_accessibility** - Automatically adjust colors for better accessibility
## Examples
### WCAG Contrast Checking
**Tool Call:**
```json
{
"tool": "check_contrast",
"parameters": {
"foreground": "#2563eb",
"background": "#ffffff",
"standard": "WCAG_AA"
}
}
```
**Response:**
```json
{
"success": true,
"data": {
"foreground": "#2563eb",
"background": "#ffffff",
"contrast_ratio": 5.17,
"text_size": "normal",
"standard": "WCAG_AA",
"compliance": {
"wcag_aa": true,
"wcag_aaa": false,
"passes": true
},
"recommendations": ["Good contrast - meets AA standards"]
},
"metadata": {
"execution_time": 0,
"tool": "check_contrast",
"timestamp": "2025-09-23T02:20:12.293Z",
"color_space_used": "sRGB",
"colorSpaceUsed": "sRGB",
"accessibility_notes": [],
"accessibilityNotes": [],
"recommendations": ["Good contrast - meets AA standards"]
}
}
```
### Color Blindness Simulation
**Tool Call:**
```json
{
"tool": "simulate_colorblindness",
"parameters": {
"colors": ["#FF0000", "#00FF00", "#0000FF"],
"type": "protanopia",
"severity": 100
}
}
```
**Response:**
```json
{
"success": true,
"data": {
"deficiency_type": "protanopia",
"severity": 100,
"results": [
{
"original_color": "#FF0000",
"simulated_color": "#c5c400",
"difference_score": 96.34,
"accessibility_impact": "severe"
},
{
"original_color": "#00FF00",
"simulated_color": "#aeb086",
"difference_score": 96.03,
"accessibility_impact": "severe"
},
{
"original_color": "#0000FF",
"simulated_color": "#0000e1",
"difference_score": 12.54,
"accessibility_impact": "minimal"
}
],
"summary": {
"total_colors": 3,
"colors_affected": 3,
"average_difference": 68.31,
"accessibility_concerns": [
"3 out of 3 colors are significantly affected",
"High overall color distortion detected"
]
},
"recommendations": [
"2 colors are severely affected by protanopia",
"Consider using alternative colors with better differentiation",
"Avoid red-green color combinations",
"Use blue and yellow for better differentiation",
"Consider using high-contrast color schemes",
"Test with actual users who have color vision deficiencies",
"Use text labels or icons in addition to color coding",
"Ensure sufficient contrast ratios for text readability"
]
},
"metadata": {
"execution_time": null,
"tool": "simulate_colorblindness",
"timestamp": "2025-09-23T02:23:08.524Z",
"color_space_used": "sRGB",
"colorSpaceUsed": "sRGB",
"accessibility_notes": [
"3 colors show significant changes for protanopia users",
"Consider using alternative color combinations for better accessibility"
],
"accessibilityNotes": [
"3 colors show significant changes for protanopia users",
"Consider using alternative color combinations for better accessibility"
],
"recommendations": [
"2 colors are severely affected by protanopia",
"Consider using alternative colors with better differentiation",
"Avoid red-green color combinations",
"Use blue and yellow for better differentiation",
"Consider using high-contrast color schemes"
]
}
}
```
## Key Features
### Contrast Checking
- **WCAG Standards**: Supports AA and AAA compliance levels
- **Text Size Consideration**: Different requirements for normal vs large text
- **Precise Ratios**: Calculates exact contrast ratios
- **Pass/Fail Results**: Clear compliance status
### Color Blindness Simulation
- **Multiple Types**: Protanopia, deuteranopia, tritanopia, and more
- **Severity Levels**: Adjustable severity from 0-100%
- **Impact Assessment**: Categorizes impact as minimal, moderate, or severe
- **Difference Scoring**: Quantifies how much colors change
- **Comprehensive Recommendations**: Specific suggestions for improvement
## Understanding Results
### Contrast Ratios
- **4.5:1** - WCAG AA minimum for normal text
- **3:1** - WCAG AA minimum for large text
- **7:1** - WCAG AAA minimum for normal text
- **4.5:1** - WCAG AAA minimum for large text
### Color Vision Deficiency Types
- **Protanopia** - Red color blindness (affects ~1% of men)
- **Deuteranopia** - Green color blindness (affects ~1% of men)
- **Tritanopia** - Blue color blindness (very rare)
- **Protanomaly** - Reduced red sensitivity
- **Deuteranomaly** - Reduced green sensitivity (most common)
- **Tritanomaly** - Reduced blue sensitivity
## Best Practices
1. **Test Early**: Check accessibility during design phase
2. **Multiple Methods**: Don't rely solely on color to convey information
3. **High Contrast**: Aim for contrast ratios above minimum requirements
4. **User Testing**: Test with actual users who have color vision deficiencies
5. **Alternative Indicators**: Use text, icons, or patterns alongside color