History of Colour::class 1 change

In crates/hub/src/diffusion.rs, lines 246–255 on 5d54cf746e00d45c6b6aaf56a134676c71e01469210c0d73fef3f1cc1f9bd32e. 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 246,255:crates/hub/src/diffusion.rs.