Improve animation overlay transparency

[JoannaMerson2]

Animation overlays and label call-outs don't display colors the same way. Transparent white overlays look too dark.

This is a screenshot from ArcGIS Pro 2.6.1.

[Tim_Hoover]

Hi Joanna, and thanks for the feedback! Fortunately, our team has already found and fixed this problem. If you upgrade to ArcGIS Pro 2.7 you should not come across this error again. If you do, please feel free to let us know so that we can further investigate what's going on.