transparentize($color, $amount) Also known as: fade_out Makes

feature_exists($feature) Returns whether a feature exists in the current Sass runtime. The

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

str_insert($string, $insert, $index) Inserts $insert into $string at $index.

join($list1, $list2, $separator:auto) Joins together two lists into one. Unless $separator

index($list, $value) Returns the position of a value within a list. If the value isn’t found, returns null instead

rgb($red, $green, $blue) Creates a Color object from red, green, and blue values.

call($name, $args...) Dynamically calls a function. This can call user-defined functions, built-in functions, or plain CSS

str_length($string) Returns the number of characters in a string.

lighten($color, $amount) Makes a color lighter. Takes a color and a number between 0% and 100%