Enum Color 

pub enum Color {
    Reset,
    Black,
    Red,
    Green,
    Yellow,
    Blue,
    Magenta,
    Cyan,
    White,
    Rgb(u8, u8, u8),
    Indexed(u8),
}

Terminal color.

Covers the standard 16 named colors, 256-color palette indices, and 24-bit RGB true color. Use Color::Reset to restore the terminal’s default foreground or background.

Variants

Reset

Reset to the terminal’s default color.

Black

Standard black (color index 0).

Red

Standard red (color index 1).

Green

Standard green (color index 2).

Yellow

Standard yellow (color index 3).

Blue

Standard blue (color index 4).

Magenta

Standard magenta (color index 5).

Cyan

Standard cyan (color index 6).

White

Standard white (color index 7).

Rgb(u8, u8, u8)

24-bit true color.

Indexed(u8)

256-color palette index.

Implementations

impl Color

pub fn luminance(self) -> f32

Compute relative luminance using ITU-R BT.709 coefficients.

Returns a value in [0.0, 1.0] where 0 is darkest and 1 is brightest. Use this to determine whether text on a given background should be light or dark.

Example

use slt::Color;

let dark = Color::Rgb(30, 30, 46);
assert!(dark.luminance() < 0.15);

let light = Color::Rgb(205, 214, 244);
assert!(light.luminance() > 0.6);

pub fn contrast_fg(bg: Color) -> Color

Return a contrasting foreground color for the given background.

Uses the BT.709 luminance threshold (0.5) to decide between white and black text. For theme-aware contrast, prefer using this over hardcoding theme.bg as the foreground.

Example

use slt::Color;

let bg = Color::Rgb(189, 147, 249); // Dracula purple
let fg = Color::contrast_fg(bg);
// Purple is mid-bright → returns black for readable text

pub fn blend(self, other: Color, alpha: f32) -> Color

Blend this color over another with the given alpha.

alpha is in [0.0, 1.0] where 0.0 returns other unchanged and 1.0 returns self unchanged. Both colors are resolved to RGB.

Example

use slt::Color;

let white = Color::Rgb(255, 255, 255);
let black = Color::Rgb(0, 0, 0);
let gray = white.blend(black, 0.5);
// ≈ Rgb(128, 128, 128)

pub fn lighten(self, amount: f32) -> Color

Lighten this color by the given amount (0.0–1.0).

Blends toward white. amount = 0.0 returns the original color; amount = 1.0 returns white.

pub fn darken(self, amount: f32) -> Color

Darken this color by the given amount (0.0–1.0).

Blends toward black. amount = 0.0 returns the original color; amount = 1.0 returns black.

pub fn downsampled(self, depth: ColorDepth) -> Color

Downsample this color to fit the given color depth.

• TrueColor: returns self unchanged.
• EightBit: converts Rgb to the nearest Indexed color.
• Basic: converts Rgb and Indexed to the nearest named color.

Named colors (Red, Green, etc.) and Reset pass through all depths.

Trait Implementations

impl Clone for Color

fn clone(&self) -> Color

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Color

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for Color

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Color

fn eq(&self, other: &Color) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Color

impl Eq for Color

impl StructuralPartialEq for Color