AVG requires updating. You can do this manually by opening the programme from the icon on your desktop and clicking on check for updates button. Make sure you are connected to the internet before doing this.
mine also goes grey every time I take on any update; my icon changes back to the coloured version on reboot ; you could try and reboot the same day to see if it will change back to the coloured version; I dont think it should really need to wait until the next day :)
the message about next update being on 29th (or whenever0 refers to the auto-update set on your computer - in other words that's when the computer intends to look again for updates all by itself . Mine does that at a fixed time everyday. You can update manually, at any time by the method described by quack. If you set AVG to recognise your internet connection you don't need to go online first - it will connect itself when you click on Check for Updates. The icon going grey can be caused by 2 different things : 1. it hasn't been updated for some time (about 10 days is sufficient to trigger this change of colour); 2. one of the standard features has been set to Off (for example, if you've turned off scanning OUTGOING mail)
the only time my AVG has ever gone gray is as quack as said it need updating, the option to update now is clearly marked, this may be an urgent update, or you have opened your date and time, or even if at the sceduled time you have set for updateing. your system was off line