History of Colour::class 1 change

In crates/hub/src/diffusion.rs, lines 245–254 on d74ce22fa80e989c9d335c5a4ace5bc3f2548b941325212210e240c3968eb537. 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 245,254:crates/hub/src/diffusion.rs.