Orange County is an extremely diverse, yet segregrated county. You'll find large groups of all races, just in different spots of OC. Usually split into two parts, north and south. North is usually considered the more "ghetto" and poorer part, while the South is richer and more plush. This is generally true. Some of the anomilies, however include:
-Yorba Linda: This city, unlike much of its North OC companions, is not a minority majority. There is lots of old money and blue bloods, beautiful homes and was rated by CNN as the 11th best place to live in USA.
-Fullerton: About 80% Asian, with 90% of those Asians being Korean. The city is also fairly wealthy, but is suffering from urbanization and white flight, so it is going down the tubes pretty quick.
-Villa Park: Another place with lots of old money, similar to Yorba Linda with slightly cheaper housing.
-Brea: There are parts of it which seem like an extension of Yorba Linda, and parts of it which seem like an extension of Fullerton, both nearby cities.
-Irvine: This central-south~ish city is the biggest bubble on the planet. Split in terms of ethnicity, about 45/45 Asian/White, with other ethnic groups making up the rest. It is like a government experiment gone wrong. Homes, streets, signals, business places, parks, EVERYTHING was preplanned. The result? Homes with no backyards, where you can reach out your window and shake your neighbors hand, streets where you must go past your original destination 4 miles to make a simple u-turn, etc. The school system, however, is rated to be excellent, which is why so many Asian people flocked there.
The rest of OC basically falls into the South - rich, North - poor.
The Orange County you see on TV is completely not true. Nowhere in OC do you find only spoiled rich snobby white kids.