The Anglican church uses single and double-breasted cassocks. For many this is to indicate tradition (single-breasted in the Anglo-Catholic tradition and double-breasted in the evangelical end of the church).
The double-breasted cassock fastens at the shoulders on the opposing side of the breast and at the waist with one concealed button. The latter usually has a single small stem-button sewn at center front about 12–15 cm / 4½–6" below the center-front neck line which is used to secure the academic hood, worn for Choir Dress.
The single-breasted cassock worn by Anglicans traditionally has thirty-nine buttons as signifying the Thirty-Nine Articles. Cassocks are often worn without a cincture and some opt for a buckled belt.
Black is the most common color for priests, readers and server cassocks. Lighter colors, such as white are used in tropical countries and some cathedrals have colors specific for their location. Piping is also used in the Anglican church to indicate position held with red being used for Deans, Archdeacons and Cathedral Canons. Bishops and Archbishops often wear purple cassocks. This has been practice since the 19th century. More recently the Archbishops have chosen to wear black. Scarlet cassocks are properly worn only by Chaplains to the Queen and by members of Royal foundations such as Westminster Abbey and some Cambridge college chapels.
Cassocks are sometimes also worn by readers, altar servers, and choir members, when they do this is the double-breasted style. Readers and altar servers usually wear black cassocks, but those worn by choirs are usually colored.
https://www.psgvestments.com/anglican-cassocks/
