rgba($red, $green, $blue, $alpha) rgba($color, $alpha)

unitless($number) Returns whether a number has units.

hue($color) Returns the hue component of a color. See

keywords($args) Returns the map of named arguments passed to a function or mixin that takes a variable argument list. The

invert($color) Returns the inverse (negative) of a color. The red, green, and blue values are inverted, while the opacity

selector_extend($selector, $extendee, $extender) Returns a new version of $selector with $extendee

mix($color1, $color2, $weight:50%) Mixes two colors together. Specifically, takes the average of each of the RGB components

zip($lists...) Combines several lists into a single multidimensional list. The nth value of the resulting list is a space

blue($color) Gets the blue component of a color. Calculated from HSL where necessary via

adjust_color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha]) Increases or decreases one