I often read that Dallas built Mustangs (P-51B-NT, C-NT, D-NT, K-NT) were Interior Greeen. The Mustangs built by North American in L.A. (P-51B-NA, D-NA and K-NA) were initially painted a darker green, sometimes called "North American Green" and, in some cases, seat in Dark Dull Green.
But no photos in my docs...