You can use jQuery's css() method to change various css properties:
$('#style').css('color', 'orange');
Inside your passage, though, you'll need to pair this with a task object like postdisplay to get it to work, since the DOM won't be rendered yet when the code is parsed.
For example:
@@#style; Some text.@@
<<script>>
postdisplay['change-style'] = function (t) {
delete postdisplay[t]; // single use task
$('#style').css('color', 'orange');
};
<</script>>