Pattern rendering on studio classic 3.5.0

[xrwang]

For a layer with a .png image as a pattern and agg-stack-blur applied, pattern is not rendered, and the polygon color is darker.
In 3.5.0 water-polygon looks like this, carto-css on right:

in studio classic 3.3.0:

[jakepruitt]

@xrwang you found a great bug here - it looks like the mix(color1, color2, weight) has been flipped from its previous functionality, now you get weight amount of color 2 rather than weight amount of color 1. Going to solve this in the next studio release.