onboardsync-react-native/src/utils/colorUtils.ts

Expo SDK for OnboardSync - Remote onboarding configuration platform with A/B testing

export class ColorUtils {
  static hexToRgb(hex: string): { r: number; g: number; b: number } | null {
    // Remove # if present
    const cleanHex = hex.replace('#', '');
    
    // Validate hex string
    if (!/^[0-9A-Fa-f]{6}$/.test(cleanHex)) {
      return null;
    }
    
    const bigint = parseInt(cleanHex, 16);
    return {
      r: (bigint >> 16) & 255,
      g: (bigint >> 8) & 255,
      b: bigint & 255,
    };
  }

  static isColorDark(hex: string): boolean {
    const rgb = this.hexToRgb(hex);
    if (!rgb) {
      // Default to light if invalid color
      return false;
    }
    
    // Calculate relative luminance using WCAG formula
    const luminance = (0.299 * rgb.r + 0.587 * rgb.g + 0.114 * rgb.b) / 255;
    
    // Consider dark if luminance is less than 0.5
    return luminance < 0.5;
  }

  static isDarkColor(hex: string): boolean {
    return this.isColorDark(hex);
  }

  static getContrastColor(backgroundColor: string): string {
    return this.isColorDark(backgroundColor) ? '#FFFFFF' : '#000000';
  }
}