Fernando Alonso to run Indy 500 retro helmet in US GP

The Spaniard elected for a retro concept during his assault on IndyCar's biggest event earlier this year, having been prompted by McLaren's decision to run his car in its famous orange colours.

Alonso battled for victory before being forced out with an engine failure at Indy, and has elected to resurrect his helmet design on his return to racing in the US.

Keeping the same red, yellow and blue lines on a black background that the Indy helmet had, the only changes revolve around F1 specific sponsors, and his race number changing from #29 at Indy to his traditional F1 #14.

Revealing the design on Instagram, Alonso said he had made the decision as a tribute to Indy and as a thanks to American fans.

F1 drivers are supposed to retain the same helmet colours for the entire season, but they are allowed to do something different at one race per year.

The regulations state that at other events the helmet must be "presented in substantially the same livery".