Michael,
From memory when the cars were current, I believe the exterior stickers / decals were white. (I hope that by decals you mean the cars' exterior badging) That goes for both Speke and Canley cars with their different designs. I've got nothing official to back it up but here's a link showing the same on a current car.
http://www.tr-register.co.uk/forums/ind ... ded&start=
My own car is Jaguar Solent blue and I decided on black badging to match the bumpers and quarter lights. In some lights they almost blend into the dark blue paint.....Even with a V8 under the bonnet it's still badged as a 7 to keep it a bit of a sleeper on the road especially when parked, to minimise the wrong sort of attention.
Adam
TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes, Anti- Dive, Granada Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. No Door Stickers. Mine since July 1986, V8 from 1991
