Hi there,
i’ve stumbled about theming Shared Folder Icons of the External Storage Support App.
Everytime i tried, i got the default Icons.
So i had a look into sourcecode. 
getIconRoute function in statusmanager.js:
There is a switch from “with themeing app” and “without theming app” … but no Code for the case of custom Theme Thing.
So the changeFolderIcon function gets that default Icon too.
I think missing the Option of own customized Themes is missing at all.
Would be great to get a small Snippet to fix it in the meanwhile.
I am not that experienced to get the var icon path to the one needed directing to the Customtheme folder.
Would be great to get a hint.
Thank you!
Chris