History of Field::colour 1 change

In crates/backdrop/src/field.rs, lines 129–144 on b6dfcb61cf5eb499420b7eee55ed6c6ca61af5e2e9f2b24772ad793e5f8a328a. 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.