      [Imgix API Reference](https://www.imgix.com/docs/reference/format#param-colorquant)
     */
     public var colorQuantization: Int? {
-        get { return _colorQuantization }
-        set { _colorQuantization = newValue?.clamped(to: 2...256) }
-    }
-    private var _colorQuantization: Int?
+        get { return storage[.colorQuantization] as? Int }
+        set { storage[.colorQuantization] = newValue?.clamped(to: 2...256) }
+    }
 
 
     // MARK: - Background Properties

        case entropy = "entropy"
    }

    // MARK: - Adjustment Properties

    /**
     Adjusts the brightness of the image.
    
     Values are clamped to the range `-100...100`.

     - seealso:
     [Imgix API Reference](https://www.imgix.com/docs/reference/adjustment#param-bri)
    */
    public var brightness: Int? {
        get { return _brightness }
        set { _brightness = newValue?.clamped(to: -100...100) }
    }
    private var _brightness: Int?

    /**
     Adjusts the contrast of the image.

     [Imgix API Reference](https://www.imgix.com/docs/reference/adjustment#param-gam)
    */
    public var gamma: Int? {
        get { return storage[.gamma] as? Int }
        set { storage[.gamma] = newValue?.clamped(to: -100...100) }
    }

    /**
     Adjusts the highlight tonal mapping of an image while preserving 
