In the US television series, The Adams Family, why were they all white?

Hey, well before the cartoon era became strong, we were treated to two actors of color, aka Amos and Andy, circa 50s. And there was Hattie Mc Daniel in Gone with the wind. The 70s afforded many actors of color to be featured.
Today cartoon characters are of color.

Transylvania was a cloudy place.
People were from places in the past. Now you create new countries, kill the natives and settle the refugees from your current wars in a hodge podge.

So where the Flintstones

I do believe Gomez was Hispanic