I think, in view of the way Fred liked to live, that you could expect the unexpected. It would have been seen to that various pranks were happening to people throughout the funeral, all kinds of crazy stuff would be going on. I do think people would be dressed outlandishly, in order to commerate Fred's personality. It would be very unconventional but still sad, of course (how could it not be?) It would just be the intention to liven things up and remember Fred the way he wanted to be remembered, as a great prankster.