Add OKLCH color space support

[kevnk]

Implements OKLCH color space support as requested in issue #3.

Adds OKLCH as a fourth export option alongside RGB, HEX, and HSL. Users can now export their color palettes in the modern OKLCH format which provides better perceptual uniformity.

Closes #3

Generated with Claude Code

[claude]

Code Review: Add OKLCH Color Space Support

Overall Assessment

This is a solid implementation that successfully adds OKLCH color space support to the application. The changes are well-integrated into the existing color export functionality and follow established patterns.

✅ Code Quality and Best Practices

Good Practices:

• Modular Implementation: The OKLCH conversion function is properly added to the color utility module alongside other color space functions
• Consistent API: The RGBToOKLCH() function follows the same naming convention and return structure as existing functions
• Mathematical Accuracy: The implementation uses proper matrix transformations for RGB→linear RGB→OKLAB→OKLCH conversion
• Integration: OKLCH is seamlessly integrated into the existing export system without breaking changes
• UI Consistency: The new OKLCH export option follows the same pattern as RGB/HEX/HSL buttons

Minor Improvements Suggested:

• Consider adding JSDoc documentation for the new RGBToOKLCH() and gammaToLinear() functions
• The gammaToLinear() helper could be moved above RGBToOKLCH() for better organization

🔍 Technical Analysis

OKLCH Implementation (color.js:306-340):

• ✅ Correct gamma correction using sRGB standard (γ=2.4)
• ✅ Proper RGB→OKLAB matrix transformation coefficients
• ✅ Accurate OKLCH conversion (chroma = √(a² + b²), hue = atan2(b, a))
• ✅ Appropriate precision (4 decimal places for L & C, 2 for H)
• ✅ Proper hue normalization to 0-360° range

Vue Integration (App.vue:474-484, PaletteRow.vue:206):

• ✅ OKLCH button properly integrated into existing button group
• ✅ Consistent styling and state management
• ✅ OKLCH data properly calculated and stored in swatch objects

🐛 Issues Found

None identified - The implementation appears solid and bug-free.

⚡ Performance Considerations

• Acceptable: OKLCH calculations are O(1) and only performed when colors are generated
• Optimization: The calculations are already optimized by being done in generateSwatches() rather than on every render
• Memory Usage: Minimal impact - only adds 3 new properties per swatch object

🔐 Security Review

• No security concerns - Pure mathematical calculations with no user input handling or external dependencies
• The database migration is unrelated to OKLCH but appears standard for Laravel session handling

🧪 Test Coverage

Recommendation: Consider adding unit tests for the new OKLCH conversion function to ensure mathematical accuracy across edge cases.

📋 Changelog Impact

The PR properly:

• ✅ Adds new functionality without breaking existing features
• ✅ Maintains backward compatibility
• ✅ Follows semantic versioning principles (minor version bump appropriate)

🎯 Final Recommendation

APPROVED ✅

This is a well-implemented feature that adds modern color space support. The code is clean, mathematically correct, and properly integrated. Ready to merge after addressing the optional documentation suggestions.

🔄 Future Considerations

• Consider adding P3 or Rec2020 color space support in future iterations
• OKLCH is excellent for design systems - consider exposing perceptual lightness controls in the UI