color

Colors without a dependency: parsing, hex, CSS output, HSL, alpha, blending and WCAG contrast.

Rgb is an 8-bit sRGB color that parses from #rgb, #rrggbb, rgb(r, g, b) or a basic CSS name; Hsl converts to and from it; mix blends two colors; contrast_ratio and best_text_color answer “is this text readable on that background”.

Install

Cargo feature color (enabled by default). To compile only this module:

cargo add helpers4 --no-default-features --features color

or in Cargo.toml:

[dependencies]
helpers4 = { version = "0.0.11", default-features = false, features = ["color"] }

Import path: helpers4::color.

Items

Item	What it does
best_text_color	Picks black or white text, whichever contrasts more with background.
BlendMode	The blend modes of the W3C Compositing and Blending specification, the same ones as CSS mix-blend-mode.
blend	Composites a source color over a backdrop with a blend mode, as the browser does for mix-blend-mode (W3C Compositing and Blending Level 1, source-over).
contrast_ratio	The WCAG contrast ratio between two colors, from 1.0 (identical) to 21.0 (black on white).
Hsb	A color as hue, saturation and brightness (also called HSV), the model of design tool color pickers.
Hsl	A color as hue, saturation and lightness.
mix	Blends two colors channel by channel.
premultiply	Multiplies the color channels by the alpha, the form a renderer composites with (a translucent color then adds to what is underneath without a further multiplication).
Rgb	An sRGB color with 8 bits per channel.
Rgba	An sRGB color with 8 bits per channel and an alpha (opacity) channel.
unpremultiply	Divides the color channels by the alpha, the inverse of premultiply.

Error types

Documented on the page of the helper that returns them.

Type	Returned by
ParseColorError	Rgb, Rgba