color-function-notation

Specify modern or legacy notation for color-functions.

    a { color: rgb(0 0 0 / 0.2) }
/**            ↑
 *             This notation */

Modern color-functions use a comma-free syntax because functions in CSS are used to group/name a syntax chunk. They should work by the same rules that CSS grammar does in general: values are optional and re-orderable when possible, space-separated, and commas are used to separate repetitions only.

For legacy reasons, rgb() and hsl() also supports an alternate syntax that separates all of its arguments with commas. Also for legacy reasons, the rgba() and hsla() functions exist using the same comma-based syntax.

The fix option can automatically fix some of the problems reported by this rule when the primary option is "modern".

The message secondary option can accept the arguments of this rule.

Options

string: "modern"|"legacy"

"modern"

Applicable color-functions must always use modern notation.

The following patterns are considered problems:

a { color: rgb(0, 0, 0) }

a { color: rgba(12, 122, 231, 0.2) }

a { color: hsla(270, 60%, 50%, 15%) }

a { color: hsl(.75turn, 60%, 70%) }

The following patterns are not considered problems:

a { color: rgb(0 0 0) }

a { color: rgb(12 122 231 / 0.2) }

a { color: hsl(270 60% 50% / 15%) }

a { color: hsl(.75turn 60% 70%) }

"legacy"

Applicable color-functions must always use the legacy notation.

The following patterns are considered problems:

a { color: rgb(0 0 0) }

a { color: rgb(12 122 231 / 0.2) }

a { color: hsl(270 60% 50% / 15%) }

a { color: hsl(.75turn 60% 70%) }

The following patterns are not considered problems:

a { color: rgb(0, 0, 0) }

a { color: rgba(12, 122, 231, 0.2) }

a { color: hsla(270, 60%, 50%, 15%) }

a { color: hsl(.75turn, 60%, 70%) }

Optional secondary options

ignore: ["with-var-inside"]

Ignore color functions containing variables.

Given:

["modern", { "ignore": ["with-var-inside"] }]

The following patterns are not considered problems:

a {
  color: rgba(var(--foo), 0.5);
}

Given:

["legacy", { "ignore": ["with-var-inside"] }]

The following patterns are not considered problems:

a {
  color: rgba(var(--foo) / 0.5);
}