if you go to Halfords they should be able to tell you the colour of your car as it is now. with a little gizmo machine that they have
if you are after it's original colour you will find a plate normally on the drivers side turret under the Bonnet with code for the original finished colours ie CCF. GHG then if you phone or look on Rimmers site you will find the code represents a colour etc etc.
[8 whole cylinders worth of punch to ram the world through the windshield and out the rear view mirror. Car & Driver]
1981 Grinnall TR7 v8
1981 Black FHC
1979 & 1980 Black Premium FHC(laid to rest) Sorry
John