There is one called betcoin.ag that has red trust users in there.
But believe they were given red because they are in that campaign already when they received it.
I haven't seen any betcoin signature campaign participant with red trust,only the owners have negative trust on their profile but this doesn't mean that they accept users who have.But believe they were given red because they are in that campaign already when they received it.
@OP I've seen some people with komodo signature and red trust maybe they are allowed to join,give it a try https://bitcointalk.org/index.php?topic=1619450