Everyone has the right to preferences, but it's not always appropriate to voice your opinions. For example some people are not attracted to darker skinned people, and that may be fine, but to say that IN FRONT of a dark skinned individual, is rude and inappropriate. It is no different when it comes to someone married to fob. They may laugh it off and not say anything to you in person- but be assured that everyone else thinks that you are a jerk for saying that and not taking into account another's feelings.
That said, always THINK before you speak. Many of these people that say stuff like genuinely mean no haraam, but DON"T THINK when they speak. It takes less then half a second to get words out, but you can NEVER take them back, no matter how much you wish you didn't say it.