public CIMPolygonSymbol ConstructPolygonSymbolWithPenInkRipple( 
   CIMColor color
)

/// <summary>
/// Constructs a polygon symbol in the specified color representing a pen and ink ripple water fill. See https://www.esri.com/arcgis-blog/products/arcgis-pro/mapping/please-steal-this-pen-and-ink-style/
/// ![polygonRipple.png](http://Esri.github.io/arcgis-pro-sdk/images/Symbology/polygonRipple.png)
/// </summary>
/// <returns></returns>
private static Task<CIMPolygonSymbol> CreateRippleFillPolygonAsync()
{
  return QueuedTask.Run<CIMPolygonSymbol>(() =>
  {
    //Ripple pen and ink
    var penInkRipple = SymbolFactory.Instance.ConstructPolygonSymbolWithPenInkRipple(CIMColor.CreateRGBColor(13, 24, 54));
    return penInkRipple;
  });
}