[442w30]

I like two-tone cars, so I tend to notice them when they appear. Still, the following that I'm going to relate is merely my experience and may not hold true as absolute fact.

When I see one, it's usually one color on the bottom and black or white on the top. Next in popularity is contrasting shades of the same color, like this Nova. I've also seen stuff like pale yellow with a green top, which matches well and is very much a combo from the era. Least popular from my experience is black or white with a color on top, such as this GTO I've seen.

In regards to the contrasting interior, don't forget that black and white match everything, so it would stand to reason that the logical color choices to match the outside would be blue (if available), black, or parchment.