Blue
From Tardis Wiki, the free Doctor Who reference
Petrol was a form of blue named after a certain oil used to energise engines within vehicles including cars and trucks.
The Third Doctor wore a petrol blue velvet blazer with a scarlet trim and a notched collar over a crimson velvet waistcoat with a gold fob watch when facing BOSS and giant maggots, as well as during Jo Grant's wedding to Clifford Jones; (TV: The Green Death) also when confronting Mark V Daleks during their Exxilon Gambit, (TV: Death to the Daleks) and when confronting Sokolov in 1970's Siberia. (AUDIO: Kaleidoscope)
