I have multiple calendars for which I am a delegate with read-only permissions. I want to be able to change the colour of them but the option is greyed out for changing colour and name of the calendar. They are all exchange calendars and are all named 'Calendar' which I cannot change either. I have added too many calendars now and iCal has made some users the same colour which makes things incredibly difficult.

When I "Get Info", both parts are greyed out and an AppleScript on 'calendars named "calendar"' would give me a gloriously monotonous pile of nonsense.
So far I have 2 red and 2 green calendars. My eyes are about to start bleeding trying to understand whose meetings are whose.