Tie for graduation

Hmm. Maybe a black textured or grenadine tie? White pindot on blue could work too. My standard job interview outfit is a navy suit with white shirt and a striped light blue/navy tie, and I think that looks pretty decent.

Perhaps a silk knitted tie in navy blue.

Just wear your college tie.

It all depends upon what sort of contrast you want. I wouldn't worry about matching to the robe. While it's what your graduation photo will be taken in, you'll spend most of the day just in the suit, shirt, tie, and shoes. Dark blue tie with Navy suit does get boring. If you want to be conservative, do something dark like black or chocolate. Maybe a dark green or violet. The thing is though, that particular combination is very standard and will work with everything, which leaves the tie open to be the center piece of the outfit. From that stand point, you're free to do almost anything, because the rest of the outfit will almost inherently support it already. Something that might take the focus of the outfit would be a bright red power tie. Sporting that with black shoes and a white linen pocket square would be very classic and at the same time probably put some bold to the whole thing. You could also play with other bold colors instead of the red, or do something with a pattern which can become bold to the point of gaudy. Something that might work is, if you want to go buy a tie, to wear the suit and shirt out to pick up the tie..

Don't wear a suit jacket under the robe. At least not if you don't want to be redfaced and sweating like a pig in photos. People really tend to over think tie and suit matching. Most suit colors are pretty damn neutral, and barring shades that are close but not quite (ie, charcoal tie with navy or navy with black), it's not an issue. Tie and shirt are, but if you're wearing white, it's not an issue at all. Wear whatever the hell you want in that regard. So you might pay some attention to the robe and hood, but I wouldn't pay too much. Those colors are regalia, and assembled without much regard to aesthetics, instead opting for their own coded meaning. I would go with the school tie. Perfect for a graduation from that school, and conveying the occasion whether the robe's on or not. Barring that, something a little more celebratory and lively than plain navy or whatever. Perhaps a navy and gold something? Burgundy/ blue? Just pick out a nice tie in a color scheme that amuses you.

I wore a bowtie for graduation this time since most robes/gowns prevent much of your clothing from being seen, anyway. I received tons of compliments for the bowtie.

I would go for the college tie, no matter how ugly you think it is (but assuming it's still kind of decent obviously).

If I could chime in as a Brit on this one, don't worry about being too warm; American gowns are indeed heavier and more closed than their British equivalents. Assuming yours is a standard Ede & Ravenscroft hire, you'll be fine. I graduated from Leeds, so I'm familiar with Yorkshire weather! For my money, a navy tie would probably be sufficiently tame to let the hood do the talking; if not plain navy then perhaps a pin dot or fine stripe. And if you're anything like me, you'll spend as long as possible in robe and hood from the moment you arrive until you absolutely have to give it back...

I agree on this one, the college tie.

Hey now... Some of us are Tits.