There’s a stereotype that all the old colonial-era meetinghouses in New England were covered with white paint both inside and outside.
Not true.
According to Peter Benes, in his definitive book Meetinghouses of Early New England, there was a wide range of exterior colors, ranging from unpainted to blue to green to orange. The Cohasset Meetinghouse was built in 1747; the first record of its exterior color dates to 1812, when it was pea-green with white trim.
As for the interior color, an architectural consultant hired for the 1986 renovation found what he thought was a bit of the original interior paint color under the pulpit. When the steps to the pulpit were remodeled c. 1837, a board was left behind with pale yellow paint marking out where the former steps were. The architectural consultant believed this was the original color. While he didn’t give his reasoning, the layer of paint is quite thin, thinner than you’d expect if it had been recoated at some point.
Pea-green outside, and pale yellow inside, not stark white. How tastes have changed over the years.