Dear Hiddy,

Having friends who work in that world, and knowing what they wear, I would go with the dark suit. I realize that you said that you hate ties, but if you can suffer one, that would be best. The event is probably only a couple of hrs, and you may even forget you have it on. Dark grey is good because it goes with just about any colour of shirt and tie combination. Perhaps, consider a cravat instead of a tie.

If you must go tie-free, wear a dress shirt, and no visible undershirt. Don't forget to polish your shoes, and that the Ambassador should be addressed as "Your Excellency".

Hope this helps.

John