How standard are 'standard' RAL colours?

[adrianreeve]

If I bought body panels from various suppliers in the same RAL colour, what chance would I have of them being the same colour? And if I got the wings from one place and the nose cone, bonnet and scuttle from another, so that the two different types didn't actually touch, do you think you could get away with a subtle variation in colour?

Cheers

Adrian