Q: Two-tone Paint
Where does the two tone split the colors?

A: Two-tone cars look just like vinyl top cars, minus the vinyl. They paint the roof one color, and the rest of the car the other color. The stainless vinyl top moldings are used for the color break. On the firewall dataplate, both colors are listed. If you've ever noticed a single color non-vinyl top car, the paint code is stamped twice, meaning upper and lower color, and vinyl top cars have the vinyl top code at the PNT designation.

--from this forum's FAQ section