Inky black feathers, for when you invoke a dark bird in surprise.
Holy Crow is a black, close to grey.
It can be described as dark, neutral, shady and dim.
Set in white, because white reads best on it.
Sacred describes something that is dedicated or set apart for the service or worship of a deity; is considered worthy of spiritual respect or devotion; or inspires awe or reverence among believers. The property is often ascribed to objects, or places.
Read on WikipediaA crow is a bird of the genus Corvus, or more broadly, a synonym for all of Corvus. The word "crow" is used as part of the common name of many species. The related term "raven" is not linked scientifically to any certain trait but is rather a general grouping for larger-sized species of Corvus. The collective name for a group of crows is a "murder".
Read on WikipediaInterjection