History of Colour::class 1 change

In crates/hub/src/diffusion.rs, lines 433–442 on 06b756358f7e15fa0441184178b46de52dd21e161d43a0dbe337234f0d96db37. 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.