Here's how to answer personal questions asked by students while you're walking across the front of the room passing out papers. "NONE OF YOUR DADGUM BUSINESS!"
Oh. Wait. You can't do that. It might hurt somebody's tender self esteem. So when, with a smirk that smacks of another desk-dweller feeding lines to a patsy, a student raises a hand to be called upon, and inquires, "Did you color your hair?" while looking around for approval from other inquiring minds, the proper answer is:
"Why would you ask something personal like that? And why would I answer something personal like that? What if I asked, 'Didn't anyone ever teach you manners at home?'"
Then the class will hang their heads in discomfort, except for one lad who tries to restore good will by answering that rhetorical question with: "I'd have to say no. Nobody ever taught me ANY manners at home. And it shows."
It's not that I mind answering such a question. I've had classes where we discussed the merits of various hair color brands and shades. That's because students were discussing it with each other, and asked my opinion. "Did YOU ever color your hair, Mrs. Hillbilly Mom?" Well, all the time. It's no secret. I don't bury the L'Oreal box under my coat when pushing my cart through The Devil's Playground. It is, however, rude to ask such a question with an ulterior motive, such as disrupting class because a boy behind you thought it would be funny. So any mouthpiece so swayed by peer pressure should be prepared to take the heat.
Obviously, these kids need a good dose of A League of Their Own, so they will understand that a lady reveals nothing. Had I answered this faux inquiry, I would have set myself up for future time-wasting inquisitions concerning tobacco/alcohol/drug use, age, romantic dalliances, prison terms, and poaching.
It's all in the intent.