That's a fascinating photo - I assume the Aero Flight titling is in red?
Do you think the patches are fluorescent orange? They do seem to be slightly brighter than the centre of the national insignia.
I can't quite determine what is going on underneath the aircraft. It looks like the same colour is also applied across the engine fairings, but I can't quite decide if it extends right across the belly to the other side. I'm inclined to think it does.
I can't imagine what the colours would have been applied for, unless it was just regarded as the accepted thing to do at the RAE back then - I guess silver with orange patches was a fairly standard paint scheme for RAE machines.