   :returns: A lighter UIColor.
   */
   public func lightenColor(amount: CGFloat) -> UIColor {
-    let amount = min(1, max(0, amount))
-
-    return HSL(color: self).lighten(amount).toUIColor()
+    let normalizedAmount = min(1, max(0, amount))
+
+    return HSL(color: self).lighten(normalizedAmount).toUIColor()
   }
 
   /**

  :returns: A darker UIColor.
  */
  public func darkenColor(amount: CGFloat) -> UIColor {
    let amount = min(1, max(0, amount))

    return HSL(color: self).darken(amount).toUIColor()
  }

  /**

  :returns: A UIColor less saturated.
  */
  public func desaturateColor(amount: CGFloat) -> UIColor {
    let normalizedAmount = min(1, max(0, amount))
    
    return HSL(color: self).desaturate(normalizedAmount).toUIColor()
  }

  /**
