I was in the fortunate position of being able to speak to Mike Trim at the most Recent Fanderson convention. AS he worked on the series, he was able to confirm that the Interceptors were all a VERY pale blue, more of a hint of blue really.
The panel in front of the cockpit, which on the dinky toy would have been chromed, should be matt Olive Drab, NOT black.
Hope this helps
Colin
http://cmtaylor.members.beeb.net/Interceptor.htm
Gentlemen! You can't fight in here; this is the WAR ROOM!