History of Field::colour 1 change

In crates/backdrop/src/field.rs, lines 129–144 on fb8aafc64f9cdf5f4166adb6f55b361410195861d21040060de95780e0d860f3. 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.