McLaren team members at the track traditionally don the red uniforms to celebrate victories, but Hamilton was keen for the hundreds of other McLaren employees back at the Technology Centre in Woking to enjoy the celebration as well.
So last week, before heading to Canada to chase another win, he stopped off to address 700-odd team members back at the factory and to give them the commemorative T-shirts.
"Winning at Monaco was a fantastic feeling and a real team effort," Lewis told the team.
"So I wanted to personally thank each and every one of you, because I'm very conscious that it's not only the race team – in other words the guys who go to the races – who make our wins possible, but also the hundreds of you back here at the McLaren Technology Centre, working every bit as hard as your colleagues in the race team.
"So thank you. Thank you so much.
"I know how hard you're working – and I really, really appreciate it.
"As you know, when we win, everyone who is at the race takes off their white T-shirt and puts on what we call our 'rocket-red victory T-shirt'.
"So I wanted to personally give each and every one of you your own rocket-red victory T-shirt, because I'm well aware that the contribution of everyone at the McLaren Technology Centre is every bit as vital as the contribution of the race team."
The presentation triggered a rush for copies of the special red T-shirts amongst McLaren's fans.
"Word is spreading on the internet that Lewis is really into his rocket-red victory T-shirts – and, as a result, they're selling like hot cakes at the moment," reported McLaren Group's head of communications and public relations Matt Bishop.
"Ever since he won so brilliantly at Monaco, and then came in to the McLaren Technology Centre in Woking to give a rocket-red victory T-shirt to every McLaren Racing employee, our merchandising guys tell me that the phones have been ringing off the hooks and that the McLaren e-shop website has been buzzing like crazy."