mode = (lightValue, darkValue, observer) => {
  const { colorMode } = observer || colorModeObserver
  return colorMode === 'dark' ? darkValue : lightValue
}
Utility function that returns a value based on the colorMode
@param {string | number | Array<string | number>} lightValue Value when colorMode is `light`
@param {string | number | Array<string | number>} darkValue Value when colorMode is `dark`
@param {import('Vue').ComponentOptions<Vue, { colorMode: 'light' | 'dark', theme: any, icons: any }>} observer Value when colorMode is `dark`
@return {string | number | Array<string | number>}