Passenger Car Interior Colors

I recently purchased several IHC streamline passenger cars with Interior Kits. The kits come in unpainted blue or red plastic. What color(s) would the interior of passenger cars have been in the 50’s and 60’s?

The most common were pale beige or gray, although very pale yellow, green, or blue were also used by some roads. Upholstery would generally have been a dark color complementing the interior color.