I have been looking for some of these answers (and others) as well.
I have been told Blue Coat and Blue Belly.
I found Blue Coat in a dictionary as well.
The person who left a web site address to follow up for Blue Belly has found the only reference to this term that I can find and I spent ages yesterday hunting the net for this term. If it is the only reference it would seem unlikely to be the answer to a quiz question as it would seem to be rather obscure.
The people organising the particular quiz I am doing for this question did get the length of one or two words wrong in their quiz of last year (on a different topic) so I am wondering if it is possible they may have got one (this one) wrong this year. It could be Blue Coat or Blue Coats (plural).
I am not sure which to use now, Belly or Coat!!