Hello Markus
I am a FlightSimmer for 6 years but a plastic modeller for.........40 years !
Now that I retired afetr 30 years on a Canadian Telecom Company, I have now a hobby that turned over the years to a professionnal activity ie Military Historian.
I am quite sure that this blue grey underside color is the correct one for a super clean "factory fresh" CL-13 Sabre.
It is the color used by the Canadian National Aviation Museum for their own real CL-13 Sabre and the color I have seen on numerous plastic modeller competiton "Winning CL-13" for both 1/48 and 1/32 Scale Categories.
For a more realistic color I would say that some weathering would be nessesary to this basic but correct color.
And yes, Its is the same 3 x color camo scheme than the Royal Air Force Sabres.
I will relay your question to a friend that is a Competition Judge for
IPMS Canada but I am quite sure I am right.
IPMS stands for International Plastic Modellers Society.
:mixedsmi:
VaporZ
By the way take a look at "Hawk One" here. I will see her fly at Bagotville Base Air Show next June 12,13,14 2009.
http://www.airshowbuzz.com/videos/view.php?v=605190c0