A black and Tan is a drink made popular in the British isles in the late 19th century. You pour a lighter "tan" beer in the bottom half of the glass, and a darker one in the top. Typically made with something like Bass and Guiness. The Black and Tans were a paramilitary force in the Irish war for independence, several decades later.
How many people got upset when Sin City the movie came out? I know it is a backwards swastika, but nazism does come to mind.
And how does recent history make any terrible deed less apauling? If you are upset about Black and Tan ice-cream, this should upset you too.
Unless you only care about tragedy in recent history relating to your nationality.