Gradient Colors in Stacked Bar chart in Qlik Sense

[mike_landow]

Does anyone have any recommendations on how, or if even possible, to color a stacked bar chart with gradient colors across a dimension? 

For example, a month-year-over-month-year chart that will show the prior year as a lighter color of the current year.  See sample image.  I'm not so concerned about the data point numbers displaying, but rather the coloring. 

I can get the colors to work across the stacked values using Master Library Measures and colors, but it does not seem possible to add a colormix type quality to those measures.

This is Qlik Sense September 2017 Release.