I think probably not. They are well known in the USA, I think.
Hmm... I think the category overall is niche. If the Guardian did a similar wall with UK entries, I'd think it was similar even if I was much more likely to know them .
On the subject of your comment on the purple ones, I'd lean to the 'hard' one being more obsolete than a straight Americanism, though I could be wrong. I struggle to think where I saw an individual use much of it, Lee Evans perhaps. Ican't remember if the term is specifically used in the Bernie Clifton's Dressing Room episode of Inside No 9 but 5ye idea is and is flagged as old fashioned. The last time I can remember seeing the term was in a review of Dave Gorman referring to him using it in the digital use.
Note, given pretty well everyone on the board has attempted this today, I think I could have used the term without it being a spoiler but I found the necessary circumlococution amusing.
