Does anyone know which white Ford used on the sapphire cosworth's in 88/89?

I thought it would be diamond white....should have checked first really. At the weekend I sorted out the tiny bit of rust on the rear offside wheel arch then painted the rear quarter panels both sides, all around the inside of the boot, under the boot lid etc etc. In the garage it looked spot on I was happy as the back of the car was looking sweet.

Anybody see where i'm going with this?

When I took the car out into the day light...oh my god, it looked as if i'd sprayed the car piss yellow!?! I know Diamond white is quite yellow anyway but this takes the piss! I've cut it back and it looks a bit better, but the more I look at it, the more its bugging me damnit!

Any ideas which white the car might be? I know its on original paint....