Following the pattern
here, I made TARDIS-esque hats for myself and my roommate.
Pictures, and more info can be found (
here).
I don't have too much info on exactly what yarn I used, since I don't really keep track of that and some of the yarn was unlabelled when I received it. Essentially, you need a black yarn, a white yarn, and a TARDIS-blue yarn of your choice (there is quite a bit of leeway on what constitutes "TARDIS blue", as you will see).
Cross-posted at
crafty_tardis