Farben

Appearance

Tips and Tricks ​

Small things that make farben nicer to work with.

Trailing Spaces When Switching Styles ​

When you switch from one style to another, put the trailing space inside the colored segment, not outside it. Otherwise the gap between words might inherit the wrong style.

rust
// Good
cprintln!("[red]Error: [yellow]something went wrong.");

// Bad
cprintln!("[red]Error:[yellow] something went wrong.");

TIP

There are cases for when you want the latter instead of the former, like backgrounds. In that case there is no conventions, like underlines. For cases where leaving any space would make it look ugly, simply immediately put [/] right after.

rust
cprintln!("[underline red]error:[/] [yellow]Without the immediate reset, that underline would partly bleed towards me! Scary...");

INFO

As of the newest version, you can now specifically reset a style/color.

rust
cprintln!("[underline red]error:[/underline] I'm still red.")

This style section has an exception:

Exception: Specific Resets ​

An exception of the trailing space rule is when specifically resetting, it's better not to use trailing spaces.

rust
// Good
cprintln!("[bold red]I'm red and bold![/bold] Now I'm just red!");

// Bad
cprintln!("[bold red]I'm red and bold! [/bold]Now I'm just red!");

TIP

The space before [/bold] would be printed while bold is still active, making it bold too. Putting the space after the reset tag ensures it's printed in the already-reduced style, which is almost always what you want.

No Spaces After Opening Tags ​

Tags apply immediately to whatever follows them. No need for a space after [red].

rust
// Good
cprintln!("[red]Hello!");

// Unnecessary space, will be printed as part of the output
cprintln!("[red] Hello!");

For the exception of the rule above.

Reset Early, Not Late ​

If you're switching between styles mid-string, reset before applying the next style rather than relying on the auto-reset at the end.

rust
// Good -- explicit reset between styles
cprintln!("[bold red]Bold red text. [/][blue]Blue text.");

// Works, but the bold bleeds until the auto-reset at the very end
cprintln!("[bold red]Bold red text. [blue]Blue text. If I'm bold, blame the guy before me.");

Escape Brackets in Instructional Text ​

If you're printing text that shows farben markup as an example, escape the opening bracket.

rust
cprintln!("To make red text, use \\[red] before your text.");
// Output: To make red text, use [red] before your text.

Prefer cprintln!() Over println!(color(...)) ​

Both work, but cprintln!() is shorter and handles the format args pattern cleanly.

rust
// Good
cprintln!("[green]Done in {}ms.", elapsed);

// Unnecessary verbosity
println!("{}", color_fmt!("[green]Done in {}ms.", elapsed));

Emphasis First, Color Second ​

When using both emphasis and color, always put emphasis first. It doesn't matter in the output, but it's significantly more readable.

rust
// Good
cprintln!("[bold green]I'm bold green!");

// Bad
cprintln!("[green bold]I'm green bold!"); // Doesn't make sense

TIP

Always sound your tag names out in English. Whichever one sounds better, go for that one.

Background First, then Foreground ​

When modifying both background and foreground values, always put background first. Again, for the same reason as above.

rust
// Good
cprintln!("[bg:green fg:white]I'm white in a green background!");

// Bad
cprintln!("[fg:white bg:green]I have a green background and white text!"); // Too long

INFO

Unlike emphasis and color, background comes before foreground because you're describing the environment first, then the text inside it. Think of it like painting a wall before placing furniture.

Idiomatic ways to bleed are on Colors And Printing.

That's it! You now know everything you need to color your terminal with Farben. Check out the API Reference for the full list of tags and functions, or browse the Project Examples for real-world usage.

Thank you for reading this documentation!