I swear I remember what seems like a few episodes of “Nova” or “Nature” that he hosted, including one where he visited the island of the colorblind, which also included a line where he was talking about his own color blindness and the time he was dropping acid and said “I want to see indigo” and was very disappointed some years later when he learned that indigo was not the vivid, bright color he saw while tripping.

Anyways, I can't quite find this info on his IMDB or wiki pages and am starting to wonder if I'm completely misremembering this.