Ummm...
If Jay is a dedicated Whovian, and
especially if he is a big fan of Tom Baker as Doctor Who, you may not want to make very many changes in stitch and color. He may most like, want, use, and appreciate a scarf as close to the original as possible.
It's problematic as to what can be considered the original, though. There were actually several different scarves which Baker used during his time in the role of the Doctor.
A search under "doctor who scarf knit" yields many pictures, patterns, color combinations, and lengths. You might consider having Jay review them and pick his favorite. If the scarf is to be a surprise, ask him if he has a favorite picture of Baker in the scarf, and then pick a pattern as close to that as you can.
IMHO, the closest to the "original" is found at
http://www.geocities.com/Area51/Zone/3746/Scarf.html
Go to "click here" under figure G. This site also gives you an idea of the passion some people feel about this scarf!