When Braniff broke out its 'flying colors' it changed the market for a short while. US liveries have for the most part been conservative and lacking any real jazz. Not so with the Europeans and others but this was one of Calder's 727s paint schemes. The tri-motor looked better in the various colors than the -8 and the 747SP.
And then you have this very rare one.
Some may not know that BI operated Concorde in an exchange with BA and flew from IAD down to DFW with Concorde for a while.. but with it required to stay subsonic, it lost tons of money and the deal was short-lived.