You know Jim that may have been its colour never really twigged as the rest of the round was painted in an iridescent green, well that will take care of the case to match that one but what colour the projectile would that have been what I call Duck Egg Blue.
I think I got this one off flea bay with a complete 40mm painted the same bloody green though cannot remember what they cost me in the end but it was not cheap........

Thanks for the reply Jim