I believe Trillian was dark haired on the radio series and in the books. The casting on the 1982 was horrendous, anyway. The new movie isn't much better.
Actually, I always thought that it was pretty good, typical for a low budget BBC show. It sort of lent a quirky "character" to the series that made it more fun to watch, in a MST3K sort of way.
Mark
Oops! Hit the wrong button. But you won't hear me disagree with you on the casting of the movie. Wow, what an awful job. In fact, that movie was one of the worst I've seen, and was one of the greatest letdowns for me in recent history.
Mark