Styling Reference

This page lists every field in AppStyles, its default value, and what it controls. It also covers the two style input formats and provides complete examples.

AppStyle variants

Each style field accepts one of two variants:

Variant	Input	Example
`AppStyle::Markup`	farben markup string	`AppStyle::Markup("[bold cyan]")`
`AppStyle::Anstyle`	`anstyle::Style` value	`AppStyle::Anstyle(Style::new().bold())`

farben markup reference

Code	Effect
`[bold]`	Bold text
`[italic]`	Italic text
`[underline]`	Underlined text
`[dim]`	Dimmed text
`[black]`, `[red]`, `[green]`, `[yellow]`, `[blue]`, `[magenta]`, `[cyan]`, `[white]`	Standard colors
`[bright_black]`, `[bright_red]`, etc.	Bright colors
`[bold cyan]`	Combined effects (space-separated)

anstyle reference

use anstyle::{Style, AnsiColor};

Style::new()
    .fg_color(Some(AnsiColor::Cyan.into()))
    .bold()

Style field reference

General help fields

Field	Default	Affected elements
`header`	`[bold underline]`	Section headings: "Commands:", "Arguments:", "Options:", "Usage:", "Aliases:"
`brand`	`[bold]`	App name and version on `--help` and `--version`
`command`	`[bold]`	Command and parameter names in listings
`command_header`	`[bold]`	Header in per-command help
`usage`	`[bold]`	Usage line content in command help
`aliases`	`[bold]`	Aliases content in command help
`dim`	`[dim]`	Secondary info: defaults, env vars, choices
`deprecated`	`[dim]`	Deprecated command names and deprecation banners

Error fields

Field	Default	Affected elements
`warning`	`[yellow]`	Reserved for future use
`error_label`	`[bold red]`	The "error" prefix
`error_kind`	(none)	Error type identifier: "unknown command", "missing value"
`error_token`	`[yellow]`	Problematic tokens: `--version`, `<target>`
`error_pipes`	`[bold blue]`	Source line and pipes in error display
`error_highlight`	`[bold red]`	Caret (^) highlighting in errors
`hint`	`[bold cyan]`	Hint messages like "run 'myapp --help'"

Complete customization example

use clish::prelude::*;
use clish::help::{AppStyles, AppStyle};

app!()
    .name("mycli")
    .version("1.0.0")
    .description("My CLI tool")
    .styles(AppStyles {
        // Headers
        header: AppStyle::Markup("[bold cyan underline]"),

        // Branding
        brand: AppStyle::Markup("[bold cyan]"),

        // Commands
        command: AppStyle::Markup("[bold cyan]"),
        command_header: AppStyle::Markup("[bold cyan]"),

        // Usage
        usage: AppStyle::Markup("[bold]"),
        aliases: AppStyle::Markup("[bold]"),

        // Secondary info
        dim: AppStyle::Markup("[dim]"),
        deprecated: AppStyle::Markup("[dim]"),

        // Errors
        error_label: AppStyle::Markup("[bold red]"),
        error_kind: AppStyle::Markup(""),
        error_token: AppStyle::Markup("[yellow bold]"),
        error_pipes: AppStyle::Markup("[bold blue]"),
        error_highlight: AppStyle::Markup("[bold red underline]"),
        hint: AppStyle::Markup("[bold cyan]"),

        // Default for rest
        ..Default::default()
    })
    .run();

Partial customization

Use struct update syntax to change only the fields you care about:

app!()
    .styles(AppStyles {
        header: AppStyle::Markup("[bold magenta underline]"),
        command: AppStyle::Markup("[bold magenta]"),
        ..Default::default()
    })
    .run();

anstyle integration

For projects already using anstyle:

use anstyle::{Style, AnsiColor};

app!()
    .styles(AppStyles {
        header: AppStyle::Anstyle(
            Style::new()
                .fg_color(Some(AnsiColor::Cyan.into()))
                .bold()
        ),
        command: AppStyle::Anstyle(
            Style::new()
                .fg_color(Some(AnsiColor::Cyan.into()))
        ),
        ..Default::default()
    })
    .run();

Color reference

Standard ANSI colors available in farben markup:

Color	Bright variant
`black`	`bright_black`
`red`	`bright_red`
`green`	`bright_green`
`yellow`	`bright_yellow`
`blue`	`bright_blue`
`magenta`	`bright_magenta`
`cyan`	`bright_cyan`
`white`	`bright_white`

For RGB colors, use anstyle with specific values.

Best practices

Consistency: Use the same accent color for headers and commands
Accessibility: Ensure high contrast between foreground and background
Clarity: Use dim for secondary information that should not compete with primary content
Errors: Keep error text highly visible with bold, bright colors