Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.13)
// Compass (v1.0.3)
// ----

// color variable map
$colors: (
  base: #FFBB00,
  light: base (lighten: 15%),
  dark: base (darken: 15%),
  trans: base (transparentize: 0.5)
);

// retrieve color from $colors map ie. `color(primary, base)`
@function color($color-name) {
  // Get value mapped to `$color` in map
  $color: map-get($colors, $color-name);
  // Get the first item from value (color or ref)
  $base: nth($color, 1);
  // Get the map of adjustments to perform (or an empty map)
  $adjust: if(length($color) > 1, nth($color, 2), ());
  // If `$base` is a key from the map, then get it 
  $color: map-get($colors, $base) or $base;
  
  // Apply the adjustments dynamically
  @each $key, $value in $adjust {
    $color: call($key, $color, $value...);
  }
  
  // Return the new color
  @return $color;
}

.foo {
  color: color('base');
  color: color('light');
  color: color('dark');
  color: color('trans');
}

SassMeister-output.css

.foo {
  color: #FFBB00;
  color: #ffcf4d;
  color: #b38300;
  color: rgba(255, 187, 0, 0.5);
}