Thanks so much for all these suggestions!
I have just ordered a cheapo lip pallate off eBay and am going to try all the colours from the comfort of home and see if I can find something that suits (or, er, matches my nipples!) and then try and find the same colour(s) in an actual lipstick.
Boots colour match is tempting but I have loads of foundation and I'm not sure I can justify buying more just to get a lipstick colour pairing.
The Blistex and Wilkos suggestions are tempting, I will definitely try these out if I see them. As much as Chanel and Mac sound lovely, I don't think I have the confidence to commit to that kind of purchase yet!