Originally posted by Wakita
do you by any chance have the paintcodes from the Citroen GT road car?
[...]
or if you can tell me how to calculate them myself...
There's no way on how to calc these codes, there's no logic behind it. You'd need to know PD's "general" list on colour codes. In case of Ramanujan's GT86(?) questioned colours, it was quite easy. These chips had a unique name which could be identified on a list of all(?) possible colour names - as they have a unique name.
I don't know, maybe that list wasn't complete. But I highly doubt it