Only way your going to figure out the original color is to find the build sheet since it will like the code for the paint. Kevin Marti can only help if you sent him a panel from the car so he can compare it to the factory fleet book (a number of us have those) and cross reference that way - since Ford didn't keep records as to what color they painted every special order paint car. On a long shot - if you car was one of a number of cars all ordered the same special paint (part of a regional promotion) there is a chance that one of the other cars in the group has already had the color determined, making the process slightly easier.
There are a fair number of pink colors used on these cars that were not Playboy pink though many (for some reason ) like to use that name
I've owned over a dozen special order paint cars and have helped restore maybe another dozen over the years. They are different but offer their own challenges
There use to be a guy that ran the Special Order Registry but he has given up the effort many years ago. Did produce a newsletter (of which I think I've got copies of most of the issues) one focused on all the pink colors and version used during the early Mustang years
......... The 7012 at the end of the DSO is in fact a paint code for the Charlotte,NC area. 275 Mustangs were ordered through the Charlotte area with the 7012 special paint code. More to come....
7012 is the cars DSO is not a paint code but the order number (from the upper left hand corner of the order form) and just the 7012th special order processed through district 22.