Resolve "Fix blue justification column header"

Prevents the headers from being colored. Also combines the four _colorize_<results-type> functions into a single _colorize_sheet function. Sheet object is now passed to colorize directly.

Shortened working stage: https://repo1.dso.mil/dsop/opensource/pipeline-test-project/java-code-evaluator/-/jobs/2889715

Another example with the full pipeline: https://repo1.dso.mil/dsop/opensource/pipeline-test-project/ubi8-minimal/-/jobs/2889976

Closes #279 (closed)