Well, I'll be the voice of dissent. I get hassled all of the time by people I do not know admonishing me for my lack of suncreen. I always wear sunscreen. I'm just red skinned, especially when it's warm out, as are my kids. I do get offended when someone I don't know pats my arm and asks "wow, I bet that hurts" or says loudly enough for me to hear "see kids, thats why you wear sunscreen, so you don't look like that lady" or asks me if I knew what sunscreen is.
I don't, out of the goodness of my heart, comment on people's food choices, shoe choices or smoking choices even if I believe it's detrimental to their well being. My skin tone is nothing I can control and it's condescending and rude for someone else to mention it, especially if you don't know me.