It's not binary. Mark Potok of the SPLC has a poster on his wall tracking the demographic decline of Whites in America. You don't need to look far - official population statistics, your kid's school, or your local Walmart - to see this massive, rapid demographic shift in action.
Even Atherton was more diverse back then.
Lives in Los Gatos: https://censusreporter.org/profiles/16000US0644112-los-gatos...