Rethink displaying arg & subcommand metadata normally and colorfully both

[HarrisonTotty]

Rust Version

• rustc 1.33.0-nightly (7bac68a5d 2019-01-21)

Affected Version of clap

• clap 2.33.0

Bug or Feature Request Summary

Currently, when one creates an application with arguments that specify environment variables via .env(), passing a flag that prints the program's help information at runtime will print environment variable information in the form: [env: NAME=], which is all expected.

The issue I wish to bring up arises when you add AppSettings::ColoredHelp (and have the corresponding feature enabled in your Cargo.toml). You'll notice that default values and possible values will be colorized, however the environment variables are not.

Expected Behavior Summary

This is more of a minor nitpick I suppose. I would expect NAME= or NAME in the [env: NAME=] substring to be colorized like how VAL in [default: VAL] is colorized.

[pksunkara]

I actually removed the colorizing for default values and possible values and aliases in #1824. I wanted to rethink quite a bit on how to display this stuff while also taking #1695 into account. I am renaming this issue.

[epage]

Another case to keep in mind is #1695

With the immediate issue being resolved (consistently there is no styling), I think #2963 supersedes this. If there are thoughts or concerns about closing this out in favor of #2963, let us know!