Trillian in 1982
Trillian in 2005
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.
I can't remembmer her name, but I had the chance to meet her, and her husband, Peter Davison (Tristan, from "All Creatures, Great and Small," The fifth Doctor, from "Dr. Who," and of course, The Dish of the Day at Milliways in the BBC series, "The Hitchhikers Guide to the Galaxy") and Mark Wing-Davie, who plated Zaphod in the original series, at a Dr. Who/HHGTTG convention in St Louis many years ago. She was beautiful, seemed very intelligent, and quite nice and easy to talk with. She (and Peter too) were very down to earth, and made lots of time to speak with individuals.
Mark