Generated by SassMeister.com.

SassMeister-input-HTML.html

<ul>
  <li class="red">red</li>
  <li class="black">black</li>
  <li class="green">green</li>
</ul>

SassMeister-input.scss

// ----
// libsass (v3.2.5)
// ----

$colors: red, black, green;
@each $color in $colors{
  .#{$color}{
    background:$color;
  }
}

SassMeister-output.css

.red {
  background: red;
}

.black {
  background: black;
}

.green {
  background: green;
}

SassMeister-rendered.html

<ul>
  <li class="red">red</li>
  <li class="black">black</li>
  <li class="green">green</li>
</ul>