Paul M. Newitt has worked out a very good reference for the hull color of the classic Enterprise NCC-1701. The hull color is "... a light grey color with a light tint of green." Here is his full report.
Important for my spaceship models is how the Enterprise looks in space.
|screenshot by trekcore.com (TOS "The Doomsday Machine")|
For my Enterprise model I used the Vallejo Model Air Color:
Barley Grey 71051 (50%) + US Light Grey 71045 (50%)