I visited Switzerland this summer and as a Tamil myself, it was the only place were my cousin and I experienced racism throughout our Europe trip. (It was in Zurich btw)
That's really unfortunate. Well there are all kinds of people in Switzerland and the farmers who have lived generations in the mountains have so so rarely seen foreigners and are extremely suspicious of them (they are suspicious even of the native Swiss who venture up into their meadows sometimes).
About your experience, well even though the Tamils are regarded so well ultimately some just view them as foreigners and so they are sometimes judged/lumped with all foreigners.