Hi Drew
I would say it's a Guardsman Blue.
I am in the final stages of organising paint and will paint my car in Guardsman blue. I saw the colour at the Run N Gun last year on a car.
I have the PPG code for the colour. Will email it to you if needed.
My email
kni-time@bigpond.com
SPF paint their cars in three blues. Portofino blue, Royal blue and Guardsman blue. Check their site here.
Cheers
Bernie