sasstest.scss

@media screen {
  %icon {
    transition: background-color ease .2s;
    margin: 0 .5em;
  }
}

@mixin icon($color, $url) {
  @extend %icon;
  background-color: $color;
  background-url: url($url);
}

.info-icon {
  @include icon(blue, '/images/info.png');
}