 Complete the following phrase:  Hamilton has worn specially designed one-off helmets for several weekends throughout his career. At the 2010 Monaco Grand Prix, he sported an altered helmet design with the addition of a roulette wheel image on the top. At the 2015 Malaysian Grand Prix, Hamilton brought with him a striking blue-and-green design in honour of team sponsor Petronas but was prevented from using the helmet by the FIA. Hamilton has sported gold coloured helmets three times in his career. After winning his fourth title in 2017, he entered 