Also Maroon, as opposed to carmine/crimson (red), was unlined initially and then lined later
I dont think you've said which branch you are referring to but a few 4575s stayed in black to the end. Then there is the choice of BR logo - St Blazey certainly had a few lined early enough to have the lion and wheel, others went straight to totem.
I'm not sure how common c83s were. A few photos around of one on the Looe branch but certainly not as widespread as the E140/145 brake composites or even the similar brake 3rds.