Function themeFromOscColor

src/utils/systemTheme.ts:60–66

(data: string)

 * Returns undefined for unrecognized formats so callers can fall back.
 */
export function themeFromOscColor(data: string): SystemTheme | undefined {
  const rgb = parseOscRgb(data)
  if (!rgb) return undefined
  // ITU-R BT.709 relative luminance. Midpoint split: > 0.5 is light.
  const luminance = 0.2126 * rgb.r + 0.7152 * rgb.g + 0.0722 * rgb.b
  return luminance > 0.5 ? 'light' : 'dark'
}

type Rgb = { r: number; g: number; b: number }