Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.3.2)
// ----

$subject_search: (
  h1 : red,
  h2 : blue,
  h3 : green,
  p : yellow,
  '.subhead' : yellow,
);
                

@mixin subject_colors($subject){
  @each $type_element, $color in $subject {
    #{$type_element} {
      color: #{$color};
    }
  }  
}

.boom {
  @include subject_colors($subject_search);
}

SassMeister-output.css

.boom h1 {
  color: red;
}

.boom h2 {
  color: blue;
}

.boom h3 {
  color: green;
}

.boom p {
  color: yellow;
}

.boom .subhead {
  color: yellow;
}