Add suport for "standard" NO_COLOR env variable

[leovilok]

See https://no-color.org

[jarun]

There's a list of utils in the link. See if they would add nnn to the list. This is useful!

[leovilok]

There's a list of utils in the link. See if they would add nnn to the list. This is useful!

I'm preparing a PR on their repo, if you want.

[jarun]

I'm preparing a PR on their repo, if you want.

Sure thing!

[leovilok]

@jarun I needed a commit ID to make the no_color PR: jcs/no_color#76

[jarun]

Thank you!

[leovilok]

@jarun nnn is now listed on https://no-color.org/

[jarun]

Awesome! Thank you!

[lawnowner]

@leovilok @jarun The informal NO_COLOR standard allows the users to have colored output in their applications only if they want to, which is a good idea, but it's not a per-application setting, and thus the applications that can output colored text and also support the standard are supposed to provide an option to explicitly enable color. Also stated in their website:

User-level configuration files and per-instance command-line arguments should override $NO_COLOR.

Right now, NO_COLOR overrides NNN_COLORS.

Also, congratulations for the anniversary!

[jarun]

I think we should honor NNN_COLORS, if it's not defined then honor NO_COLOR, if none of the 2 defined show default colors.

@leovilok can you please take care of this? No hurry but please keep the change minimal.

[leovilok]

@jarun @lawnowner see #515