I'll be happy to compare a few samples, so I'll send you my address.
Re: the "grey" vs. "gray" point, I wasn't referring to differences in day-to-day spelling between US and UK English. The RAF colours are official names, so their spelling should be with an "e". As Mal points out, if you don't use the correct RAF names, it will reflect negatively on how thoroughly you've researched your products.
I've just had a look at the RAF Museum chip for Azure Blue in overcast daylight and, as you suggest, there is a hint of purple - but it is only the faintest hint. FS 35231 is often sited as a match, but the RAF Museum chip is a good deal paler than FS 35231 in my FS 595B Color Fan.
All the best
Rowan
