Simple list-usage in Sass: color-list

color-list.css

.color-list li:nth-child(1) {
  background-color: #cecece;
}

.color-list li:nth-child(2) {
  background-color: #656565;
}

.color-list li:nth-child(3) {
  background-color: #5f5f5f;
}

.color-list li:nth-child(4) {
  background-color: #f6f6f6;
}

color-list.scss

// ----
// Sass (v3.3.0.rc.3)
// Compass (v1.0.0.alpha.18)
// ----

$col1: #cecece; 
$col2: #656565; 
$col3: #5f5f5f; 
$col4: #f6f6f6; 

//  add colour to each piece.
$colors-list: $col1 $col2 $col3 $col4;
@each $current-color in $colors-list {
  $i: index($colors-list, $current-color);
  .color-list li:nth-child(#{$i}) {
      background-color: $current-color;
  }
}