Select foreground light/dark color based on background color

foreground-color-selector.ts

/**
 * Selects light or dark color for foreground (mainly text) based on background color
 * @param bgColor Background color to evaluate
 * @param lightColor Light foreground color (defaults to white)
 * @param darkColor Dark foreground color (defaults to black)
 * @returns Light or dark color based on background color
 * @see https://stackoverflow.com/a/41491220
 */
function pickTextColorBasedOnBgColorAdvanced(bgColor: string, lightColor = '#FFFFFF', darkColor = '#000000'): string {
  const color = (bgColor.startsWith('#')) ? bgColor.substring(1, 7) : bgColor;
  const r = parseInt(color.substring(0, 2), 16); // hexToR
  const g = parseInt(color.substring(2, 4), 16); // hexToG
  const b = parseInt(color.substring(4, 6), 16); // hexToB
  const uicolors = [r / 255, g / 255, b / 255];
  const c = uicolors.map((col) => {
    if (col <= 0.03928) {
      return col / 12.92;
    }
    return Math.pow((col + 0.055) / 1.055, 2.4);
  });
  const L = (0.2126 * c[0]) + (0.7152 * c[1]) + (0.0722 * c[2]);
  return (L > 0.179) ? darkColor : lightColor;
}