Curious what those actually living in or from the region perceive as to the racial climate there in Chile and Sourh America in general.
The much larger problems are class and sex discrimination. There is definitely a "nanny" class that the middle/upper income people view differently and vice versa. You would be largely exempt from this as a foreigner and would have no problems interacting with both groups. For women, the sexism is an obstacle although not a huge one. Offhand I can think of five female entrepreneurs I know personally in the tourism industry. They are from Chile, Cuba, Austria, US, and Argentina.
Chileans are overall very respectful of foreigners. They are self conscious due to Chile's small population and are open with foreigners and appreciate what they bring to the table.
There are very few black people. I have talked to a few that are US basketball players on contract to local teams for a year or two. They generally seem to enjoy the experience. Brazil has more blacks but it also has more corruption, more crime, and a higher cost of living.
Whatever you decide, I highly recommend living abroad as there are few better learning experiences.
A friend of mine recently posted (FB) the following story on the police blitzing a black foreigner for jaycycling: http://www.emol.com/noticias/nacional/detalle/detallenoticia...
I'm inclined to say the same about Argentina and Uruguay, where I've traveled a few times, but not lived. I've also been to Brazil, and can tell you people of darker skin are quite the norm, as in the caribbean like Venezuela, though I wouldn't recommend going there for other reasons.
disclaimer: I've never been to Chile, so I'm not sure if any of this applies there...