Sure we can do this - we know how to re-add an icon.
But it would be nice to know why the icon changed to the green droid. But its not that important....
Ja sure - you can just delete it and put it back from the app drawer.
Yesterday was an update of google+ - after that, my g+ icon on my homescreen switched to green droid, too.
So I think it?s all caused by the updates....
Same here on a Nexus 7.
I?m using a modified CM - few days ago the chrome icon in a folder changed to a greed droid. In the app drower is the correct one.
Maybe we get an award? :-)