Blacks were virtually nonexistent in Orange County in the 60s, the exceptions being Santa Ana (retired and military families), Fullerton (sports) and San Clemente (Marine Corps at nearby Pendleton).
Plenty of Hispanics, and a few Asians too, both of whom were included in my circle of friends.
My high school town's demographics have changed quite a lot, toward Hispanic--but neighborhoods are still very nice. These are 2nd, 3rd, 4th generation people that are essentially living the middle class American lifestyle.
When we were in Colorado a few years ago, we visited the town I lived there. We walked the street where my father built a home, and we lived for awhile. I approached an older fellow, sitting on his front porch, but he spoke little English. His daughter came out, and we talked awhile. It turns out the family moved away from Lost Angeles, seeking a better area--after the 1992 Rodney King riots.