History of Colour::class 1 change

In crates/hub/src/diffusion.rs, lines 433–442 on a74ba3cb45110de2d93ca6a30715294f4a59b6bdf7f1b957125985b4dcb9794c. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 433,442:crates/hub/src/diffusion.rs.