Gibson named his dog because it was a black Labrador. At that time Gay meant happy and carefree, Robertson's used a Golliwog trade mark, and the badges were much collected. As for American attitudes to black people at the time, just do some basic checking into US Armed forces history. Britian was the enlightened country at the time, unless you were Welsh or Irish.
It's called history and social change. Who knows what will be made of our comments in ten years, let alone fifty or sixty.
Think of the attitude to couloured shirts for men and long hair in the late 1960's.
(Not to mention the effect of Hot Pants and Mini skirts on impressionable youths of that era! )