- Introduced utility functions for color manipulation: `fhHexToRgb`, `fhRgbToHex`, `fhMixHex`, `fhRelativeLuminance`, and `fhContrastText`.
- Implemented a comprehensive theme palette based on the user's favorite color, including primary, secondary, and semantic colors.
- Updated CSS variables in the stylesheet to reflect the new theme structure, enhancing consistency across the UI.
- Modified header to dynamically apply theme styles based on the generated palette, improving visual coherence.
