Yes good points both, thank you. The source code link has more explanation about color choices and my preference of POSIX compatibility. You can also see the color function that checks NO_COLOR, CLICOLOR_FORCE, TERM = "dumb", -t 1, etc.

For color operands, I use raw escape codes because I aim for POSIX compatibility. If I'm working on something that needs more capabilities then I switch to a more powerful programming language e.g. python, rust, etc.

As far as I understand, POSIX tput defines some terminal operands (clear, init, reset, etc.) but not color operands (setaf, setab, sgr0, etc.).