Distribution plot: gradient box color

[lerouxlarissa]

Has anyone tried to set the fill color of  a distribution plot box to a gradient color? 

The grey "box" (see image),  should be a gradient color, for example black on the left and white on the right.

I have tried to do this with a json theme (see code), but was unsuccessful. I was however successful in changing the box fill to a single hex color, but would like  a gradient instead. 

Any ideas regarding this would be greatly appreciated. 

  "distributionPlot": {
      "box": {
        "fill": 
 {
      "type": "LinearGradient",
      "stops": [{
        "color": "red"
      }, {
        "color": "blue"
      }]
    }
      }
    }