Mr Blue (real name unknown)
Mr Blue is an old man. He is seen smoking a cigar at the diner.
Not much is known about mr blue because he has two lines of dialogue in the film.
Mr. Blue's death is not seen by the viewer during the film. Joe explains in the film's final scene that he was killed - presumably he was shot by the police. In the Reservoir Dogs video game, however, it is shown that after escaping from Karina's Wholesale Diamonds, he entered a movie theatre where he was then shot by the police. This may have been his real fate in the film.
An interesting thing to note is that when Joe Cabot (Lawrence Tierney) is talking to the rest of the film's cast in the warehouse before he assigns them each of their colour-coded names, he says "Five guys sitting in a ballpen, in San Quentin". This is ironic considering that Eddie Bunker did time in San Quentin State Prison.