This tea cosy is supposed to resemble battenberg cake. Only it doesn't really, because the yellow is too dark and the pink is too pale.
This is a lesson for me, when I'm trying to colour match: better trust my own eyes to render colour accurately, not my monitor. Or, buy the actual recommended yarn in shades as stated in the pattern.
In case battenberg cake is not widely known outside the UK, I'll include a photo of this traditional English tea-time treat:
It is actually plain sponge, some with pink food colouring, sandwiched together with apricot jam and then surrounded in a layer of marzipan (almond paste). Sounds rather sickly, when I describe it, but in fact, it's wonderful. (Note: I had to buy a cake in order to take this photo, as it's far too fiddly to contemplate making my own, but it was no hardship, honest.)
The recommended yarn was James C. Brett Top Value. Now ordinarily, I avoid acrylic like the plague, preferring the handle and drape of other yarns - which are sadly much more expensive. But this time, in the interests of authenticity, I obtained the recommended yarn from ebay. It was super cheap, and the colour match is much closer*:
I've got loads of yarn left, so I can see Battenberg tea cosies forming a mainstay of future gifts. As this pattern is knitted double on 5.5mm needles, it takes only a couple of hours from start to finish. (In case anyone else wants to try this pattern, it is included in Tea Cozies 2)
*obviously, the handle is not quite so marvellous. But I daresay my teapot won't even notice.