Theirs were knit with the most accurate colors I could lay my hands on in 100% acrylic so easy wash and easy dry for Mom. (www.doctorwhoscarf.com has everything you need to know if you want to make yours)
Mine, however, was knit with Cascade Pacific, 40% super wash Merino/60% acrylic, in the colors most closely related to the proper colors. It's not really that close but they were what was on hand at Knitorious in St Louis.
(This pic doesn't really show the colors very well.)
I probably never would have used this yarn had it not been for this project but I really enjoyed knitting with it and the Merino gives it enough softness that I'm seriously considering it for a new sweater. 213 yards in the skein so you could definitely do something cool for a reasonable price.
It would be a perfect pick for a modern take on a fair isle pattern.