Team Sky started Stage 1 of the Tour de France in yellow helmets. This is thanks to a new rule - highlighted above - where the leading team in the race which stipulates all riders on the leading team must wear yellow helmets provided by their team. In addition they get special yellow race numbers to stick on their backs.
The team prize is determined by the overall time of the best placed three riders from each team.
The yellow helmet rule might be new for 2012 but it’s not that novel. In the 1970s and 1980s riders on the leading team wore yellow cotton caps, back in the days before riders used helmets.