_hda.scss

// Hexadecimal Alpha Colour function
@function hda($hexdec: null, $alpha: 1)
{
    @if $hexdec == null {
        // throw error if no value supplied for $hexdec
        @error "$hexdex cannot be null: was, NULL";
    } @else {
        // evaluate input
        @if $alpha >= 1 {
            // return plain hexadecimal value if $alpha is greater than or equal to 1.
            @return $hexdec;
        } @else {
            // otherwise return an rgba value with an alpha value.
            @return rgba($hexdec, $alpha);
        }
    }

}