i think it depends on your relationship with the other person. i call one of my best friends a "creepy ginger" all the time, but he knows its more a term of endearment than anything. however, if the use of such terms offends other bystanders, it is wrong. keep in mind that if you are at work flirting with a female co-worker who is 100% ok with it, but the devout religious lady at the next table overhears you say she's whatever term you want to use for "attractive" and is offended enough to go to HR, you cab still get fired for Sexual Harassment or what have you based on the topic if conversation in question.