code: function darken(amount: number | string, color: string): string {
    if (color === 'transparent') return color
    const hslColor = parseToHsl(color)
    return toColorString({
      ...hslColor,
      lightness: guard(0, 1, hslColor.lightness - parseFloat(amount)),
    })
  }
docs: Returns a string value for the darkened color.
  
  @example
  // Styles as object usage
  const styles = {
  background: darken(0.2, '#FFCD64'),
  background: darken('0.2', 'rgba(255,205,100,0.7)'),
  }
  
  // styled-components usage
  const div = styled.div`
  background: ${darken(0.2, '#FFCD64')};
  background: ${darken('0.2', 'rgba(255,205,100,0.7)')};
  `
  
  // CSS in JS Output
  
  element {
  background: "#ffbd31";
  background: "rgba(255,189,49,0.7)";
  }