At any rate, back to the craft store we went today, because I'd completely forgotten about one of the colors I needed. I was looking for a medium brown, but all they had was dark brown and might-as-well-be-black. There was more appropriate colored yarn in acrylic, but I'm not about to mix acrylic with wool, no sir. Dark brown it is- and it doesn't look too shabby. It won't be exactly like Tom Baker's, but Remy's not particular about every little detail.
I also got some tapestry needles (for color switching) and a crochet hook (which I don't know I'll need at any point; more of an insurance measure).
So I'm about 27 rows in now, and have successfully switched colors twice. The color-switching involves sewing the loose ends of both the old and new colors into the scarf, which makes me happy, as I'm far more adept at sewing than knitting. I am getting better/faster at the knitting as I go, though. =) My right index finger's getting a little calloused, but no big deal.