Hmmm... what a good discussion.
I don't know if anyone here so far is coloured, so I thought I'd add my thoughts.
I've lived in CH-land for 5 years. 2.5 years in Olten saw a few racist attitudes like when my husband (white) and I would go for a walk, 99% of the time, we get wished like everyone else, but occassionally, we'd see the look from right to left, left to right and finally as we're about to pass, a distinct look away with no greeting. In order to prove our existence, we would normally walk right in front of the person and say Gruetzi very loudly (hopefully within earshot of all other passers-by).
The old man next door hated us but we're not sure if it's just us or everyone else. But we treated him the same way (ie. walk right up to him with a loud Gruetzi). But we had plenty of other old people who would come up and try to speak to us (who hardly spoke any german at that time).
Apart from that, I've worked in Bern and in Zurich and to date, I'm with my 4th company - 3 swiss and one multi-national. I've been told by a recruitment agent that there are three things against me when someone sorts out their received job applications:
1. My name that's hard to remember
2. Not speaking german fluently
3. Being female
I've been living in Zurich for almost 3 years. I've not come across anything at all that I would consider racism. I don't perceive any change of attitude towards me but having said that, I should be fair to point out that I dress westernly - albeit with colours (shock horror!) and have a very open demeanour (I've taken to increase the smile percentage in Zurich). So this is a far cry from a black man sitting on the tram with what looks like a scowl on his face. Chances are the seat next to him will be the last one taken.
But don't we all go through some sort of subconcious choice when we have to pick who to sit with on the tram?
Foreigners are relatively new to this country so it's not surprising that they're way behind when it comes to "how to deal with it".
But changes are slowly taking place in this closed society. Just with food, the numbers of foreign eateries has just kept increasing and generally you will find swiss people in these places. Betty Bossi now has come a long way from what used to be around 5 years ago.
Yes, they're blunt and they're not politically correct and I'm not trying to say that their policies aren't racist, but on a society level in Zurich, I've not personally faced any problems as a coloured person.