The red Omegas were attached to the Diplomatic Protection Group (DPG ) and they came about after various foreign embassies complained about the fact that they needed to actually see the cars attached to the group and to reassure the diplomats of their presence.... hence the colour red.
The car in the picture belongs to a serving SO19 instructor, and I'm in touch with him, but as he's not an OOF member, I won't name him.
hopefully this clears up the mystery of the red Omegas.