The hood or under the trunk lid will almost always offer good color; or if you happen to pull a door card off, many times you'll find good color there, as well.
Lilac might be a possibility for the darker shade, too. That was a 1966-1967 shade, but it could've been earlier as a different name? Either that, or my eyes are really going to hell on me.
If you know a quality detail shop and the paint has not burned through to primer, you might look into what's called a "paint correction" to bring out the real shine on your existing paint. Not a cheap detail job! Depending on where you are at, it can run from $400 up to $900. That also includes the ceramic coating, which a quality shop guarantees for two years. I'm having this done to my Imperial before our Southern Plains Mopar Fest in June.