I had a slightly different problem with Rosso Monza. I bought a 430 Scuderia for La Festa Howeveryouspellit, it was Monza Red (Rosso Monza... whatever) and looked sweet.
I won it and got the California. It was black so I thought, "hey, I have this Monza Red paint chip, why not paint it to match the 430?" Unfortunately, when applied to the California, it was a horrible pale rose color instead of the nice deep red I wanted.
It has since been repainted again and is now Mazda K2RED.
A similar thing I noticed, Nissan Ultimate Opal Black (from the GT-R VSpec) loses most of its purple shift when applied to another car. It looks awesome on the GTR, not so much on anything else, although the shift is still there if you look closely.