<===> input.scss
$map1: (
   red: 'bar',
  'red': 'foo',
);

$map2: (
   red: 'bar',
  'red': #{red},
);

.foo {
  content: inspect($map1);
  content: inspect($map2);
}
<===> output.css
.foo {
  content: (red: "bar", "red": "foo");
  content: (red: "bar", "red": red);
}