How can I tell if COLOR is correct on XK 120?

Hi, just entering the world or xk 120's and have the book "ORIGNAL XK" Restoration.
I have noted the color charts pertaining to dates in the rear of the book, but am wondering if there is a more difinative way of determining the correct color of a car. (I am hunting some down and want an orig fact respresentation.)

Is there anything on the body that should tell me? Are there any records if I prvide VIN or chassis numbers?

Thanks in advance fo the help.