Shade Color

export function shadeColor(color, decimal) {
  const base = color.startsWith("#") ? 1 : 0;
 
  let r = Number.parseInt(color.substring(base, 3), 16);
  let g = Number.parseInt(color.substring(base + 2, 5), 16);
  let b = Number.parseInt(color.substring(base + 4, 7), 16);
 
  r = Math.round(r / decimal);
  g = Math.round(g / decimal);
  b = Math.round(b / decimal);
 
  r = r < 255 ? r : 255;
  g = g < 255 ? g : 255;
  b = b < 255 ? b : 255;
 
  const rr =
    r.toString(16).length === 1 ? `0${r.toString(16)}` : r.toString(16);
  const gg =
    g.toString(16).length === 1 ? `0${g.toString(16)}` : g.toString(16);
  const bb =
    b.toString(16).length === 1 ? `0${b.toString(16)}` : b.toString(16);
 
  return `#${rr}${gg}${bb}`.replaceAll("-", "");
}

shadeColor("#265c98", 1.5); // #193d65 - darken the color by 50%
shadeColor("#265c98", 0.5); // #4cb8ff - lighten the color by 50%