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Clap Version

4.3.3

Describe your use case

From #3234 (comment)

I cannot find the style to use to change the appearance of the default and possible values. They always appear white. Is that not currently supported?

I understand that this might not be directly related to this issue, so I can open a new one if that's more appropriate.

Describe the solution you'd like

Allow styling to either help it stand out from the rest of the description

Alternatives, if applicable

No response

Additional Context

From #3234 (comment)

Besides naming the styling element for defaults, possible values, and env variables, I'm curious on how people think we should style it.

Some options I thought of:

* `{spec}[default: true]{reset}` (all styled the same)

* `{spec}[default: {literal}true{reset}{spec}]{reset}` (outer-styled, value stuled)

* `[{spec}default:{reset} {literal}true{reset}]` (key-styled, values-styled)

So long as we only use new style definitions, it is not a major or minor breaking change according to our support policy. See https://github.com/clap-rs/clap/blob/master/CONTRIBUTING.md#compatibility-expectations