Examples of colored help/errors?

[epage]

Please make clear if this is

• An idea or prior art from an application (clap or not)
• Motivations for choices, if available

In Clap v4, we made the color palette more neutral because

• Terminal styling was not customizable
• Our default colors were bad generally (warning color for a header?)
• Our colors clashed with branded coloring (Make colored help output more compatible with an applications overall theme #2963)

Now that we have customizable terminal styling, I figure it would be good to see how people have been using it to help with

• Sharing of best practices across applications
• Maybe changing of the default in clap v5 (we consider this a breaking change despite it not programmatic output because it would significantly diverge from people being consistent with it)

Limitations for clap defaults:

• [4-bit color](https://en.wikipedia.org/wiki/ANSI_escape_code#3-bit_and_4-bit( to ensure it works with the users color scheme
• Bold and underline only for styling effects
  • Italics is handled poorly by some terminals, e.g. doing nothing or inverting colors
  • Dimmed might be possible but some users have reported their terminals make this too unreadable

[epage]

clap v4's style

[epage]

Cargo's style

[epage]

I'm partial to this

• Its a general style and not related to branding
• Cargo went with these colors for many years for regular output without complaint

[epage]

I wonder about adding Underlining to headers

[epage]

clap v2

[pksunkara]

I used this style in my apps, but changing placeholder to cyan and usage to yellow.

    Styles::styled()
        .header(AnsiColor::BrightYellow.on_default())
        .usage(AnsiColor::BrightYellow.on_default())
        .literal(AnsiColor::BrightGreen.on_default())
        .placeholder(AnsiColor::BrightCyan.on_default())

[epage]

Is there a reason you kept to the clap v2 colors or made the tweaks you did (if I even got the colors right...)

[pksunkara]

There were 3 thoughts I had:

1. I wanted to use the old clap colors to maintain the style.
2. Updated the placeholder style to differentiate it (can be considered as style improvement over 1)
3. Updated the usage style to be similar to headers (can be considered as style fix over 1)

[pksunkara]

And tbh, both 2 & 3 points were possible with the changes in v4. So, I thought of them as incremental improvements to the older style.

[nbari]

Just in case, I use this similar to cargo defaults or clap 2:

 let styles = Styles::styled()
        .header(AnsiColor::Yellow.on_default() | Effects::BOLD)
        .usage(AnsiColor::Green.on_default() | Effects::BOLD)
        .literal(AnsiColor::Blue.on_default() | Effects::BOLD)
        .placeholder(AnsiColor::Green.on_default());