<!DOCTYPE html>
<html>
<style>
    :root {
        color: green;
    }
    @media (scripting: initial-only) {
        :root {
            color: red;
        }
    }
</style>
<p>This text should be green when printing.</p>
<script>
if (window.internals)
    internals.settings.setMediaTypeOverride("print");
</script>
</html>