History of Colour::class 1 change

In crates/hub/src/diffusion.rs, lines 433–442 on d366306dae7d601bf141448c5454b89299847bb45ce14f84a23ffd13906a1c24. 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.