$colors: (
    primary: #0000FF,
    primary-light: lighten(#0000FF, 40%),
    primary-dark: darken(#0000FF, 40%),
    accent: #FFF6BB
);

$padding: 15px;
$border: 15px;


/* function declared */
@function color($color-name) {
    @return map-get($colors, $color-name)
}

/* Usage */
span {
      background-color: color(primary-light);
}