History of Field::colour 1 change

In crates/backdrop/src/field.rs, lines 129–144 on ffb67a81188c4cdc0abc3697121000cef9d31950af99495923285770c7d602c0. 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 129,144:crates/backdrop/src/field.rs.