You cant. No one wants to be called a racist or accused of being racially insensitive. The people who gravitate to these kinds of positions tend to be extremely fanatical and they have the willingness and power to make your life miserable if you don't go along.

If you just want to do your job as best as you can you just have to compromise - otherwise, you run the risk of getting sidetracked by this kind of stupidity. It's easier - and in the short term, more productive - to just acquiesce.