I downloaded Avast today and although everything seems to downloaded ok the ball in the icon tray is still gray. Isn’t it suppose to be blue and protecting?
Grey is good, the colour is not a bright blue, to me it looks a blue grey but many factors, monitor, graphics, background colour will effect how it looks to you.
So long as there is no Red bar across it, no problem, you should also see ashDisp.exe running in task manager. It should also rotate when scans are being done.
It’s very light grey when the providers are paused or terminated, but I suppose that’s not the case here. 
Depending on colordepth and so on…
As long as it rotates now and then everything is fine. (Not during an on-demand scan, that is.)
HL