- Implement tests/run_tests.sh with mocked environment
- Cover color conversion, multi-format output, and config loading
- Verify clipboard and notification integrations via mocks
- Document testing procedure in README.md
The `--alpha` flag and `alpha = true/false` config file options remain
functional but references to them are removed as they are now superseded
by the output formats with alpha channels (rgba, hexa, hsla).
New users/configurations should use the relevant output formats. The
legacy flag/options remain active for backward-compatibility with older
configs/scripts.