From ESPNF1: "The switch back to the colour, long associated with McLaren and its early days in motor racing, has been rumoured and teased for months since Zak Brown took over as team CEO following Ron Dennis' departure from the McLaren Group. The break from the Dennis era goes further than the livery, with the 'MP4' prefix --standing for Marlboro Project Four and used for its F1 car names since Dennis' arrival in 1981 -- dropped in favour of the all-new MCL."