help with paint code

hey im painting my 68'mustang but im having a hard time finding the paint code for the interior paint. the tag thats supposed to be on the firewall isn't there so if anyone has a book or if they know a good way to get the paint code please help. its like a tan color, i think it's called parchment or pebble beige but i can't find the code, thanks for the help.

well mines no 68... but its where the door latches on mine.

yea all thats on the door on my car is an interior trim code, all that tells me is that i have a standard interior with bucket seats