2) Saying something like, "I'm sure you didn't mean any harm, but your comments about my attire could be taken as an insult. Perhaps we should change the subject."
3) Asking a manager to speak to specific co-workers and, without naming names, remind them that comments about a colleague's appearance are, if not illegal, at least inappropriate.
Dear Social Grace,
I'm throwing a wedding rehearsal dinner for my son's upcoming nuptials and wondered what type of toast is correct, or is there anything I'm expected to say that would be appropriate?
Since you're the host, the first toast would be your privilege and obligation. The good news is that in most toasting situations, brevity is an appreciated (and highly underrated) attribute. And at a rehearsal dinner, specifically, many other people will probably be making toasts, so you can quite properly keep yours short and to the point. If public speaking isn't something you enjoy, don't worry about having to wax too poetic.
It's often customary for the groom's father to offer a simple toast to the bride's parents at the rehearsal dinner -- for instance: "I would like you to join me in toasting Joanna's parents, Matt and Christina Drayton, two wonderful people we are honored to welcome into our family." Thereafter (or instead of that toast, if it isn't appropriate for your situation), you can propose a toast that follows this format: Compliment your future daughter-in-law, welcome her into your family, and wish the new couple happiness.