Is it possible your car is a '66 model? Post the VIN and we can be sure. The '66 models did not have a white interior option like the '65 models; it was replaced with a light tan color called Parchment (the exception was on the two-tone deluxe interiors blue/white, aqua/white, and ivy gold/white where the '65 white was used). This sounds like the color you're describing. Unfortunately, the color library does not list the PPG code for Parchment.
Give us more of a description of your interior. If it's a '66 Parchment interior it will be all Parchment on painted and vinyl surfaces with a second color for carpet / dash pad / dash hardware / seat belts. These pieces are called "appointments," and could be black, blue, aqua, ivy gold, or burgundy.
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