I think it is a type of maroon.
Explanation:
Commedia dell'arte, a traditional Italian form of physical comedy, uses masks and often they appear in Elizabethan and Restoration comedies, where a character might use one as disguise. In Greek theatre the actors all wore exaggerated masks to communicate character.
I believe it changed due to the change of culture in the era. When you look at modern architecture it looks totaly different from 40 some years ago. Because of this change in the architecture, since most likely it was the culture change it was significant to the eyes of the church-goer of the time because no one has seen anything like it.
