Evaluate switch to `termcolor`

[b1rger]

termcolor supports the NO_COLOR environment variable and seems to be maintained

[b1rger]

BurntSushi/termcolor#30 says:

There will probably come a day when I no longer want to support the old console APIs. I don't know when that day will come, but it's not today. And when it does come, I'll likely deprecate termcolor (or hand off maintenance to someone I trust) and then switch to something like the ansi_term crate.

therefore closing