I think both TWA and UAL have very classy liveries. I am doing 1/144 plastic models using both - TWA 757-200 and UAL 747-400.
I haven't been able to figure out the exact shade of TWA's dark blue lower fuselage; in some light, it looks almost black, in others, deep blue. It really looks amazing with the red and gold, though. I also love the contrasting dark blue and grey on UAL's planes, as well as the dark blue engine nacelles. By the way, the cheatline stripe is a take-off on the old UAL red and orange stripes, not the Pride flag.