function getRgb(color, alpha) {
  if (color.length === 4) {
    color = `${color}${color.slice(1, 4)}`;
  }
  const r = parseInt(color.slice(1, 3), 16);
  const g = parseInt(color.slice(3, 5), 16);
  const b = parseInt(color.slice(5, 7), 16);
  const a = alpha || 1;

  return `rgba(${r}, ${g}, ${b}, ${a})`;
}
hex to rgb
@param {string} color - hex color
@param {string} alpha - color alpha value
@returns {string} rgb expression