Generated by SassMeister.com.

SassMeister-input-HTML.html

<a href="#" class="example1">Hover over Me</a>

<a href="#" class="example2">Hover over Me</a>

SassMeister-input.scss

// ----
// Sass (v3.3.8)
// Compass (v1.0.0.alpha.19)
// ----

@mixin link-colors($base-color, $new-color: darken($base-color, 30%)) {
  color: $base-color;
  
  &:hover {
    color: $new-color;
  }
}

.example1 {
  @include link-colors(tomato);
}

.example2 {
  @include link-colors(green, blue);
}

SassMeister-output.css

.example1 {
  color: tomato;
}
.example1:hover {
  color: #ad1a00;
}

.example2 {
  color: green;
}
.example2:hover {
  color: blue;
}

SassMeister-rendered.html

<a href="#" class="example1">Hover over Me</a>

<a href="#" class="example2">Hover over Me</a>