[Theme: WPFolio Two] Multiple blog categories?

Hello,
I have made a child theme from WPFolio two in order to change some styling around. The theme allows setting one blog category that is styled differently than the rest of the category pages. I would like to figure out how to modify it to allow multiple blog categories. Ideally I could somehow do this in my child theme.

I think this is the relevant part of wpf-functions.php that changes the blog category styling:

// Add portfolio body class to anything that isn't the blog
function portfolio_body_class($class) {

	global $post, $blog_catid;

	if ( in_category($blog_catid) || is_home() ) {
		$class[] = 'news';
		return $class;
	} else {
		$class[] = 'portfolio';
		return $class;
	}
}

add_filter('body_class','portfolio_body_class');

The current blog category in the above example is “news.” I would like to add a couple more categories that are excluded from the portfolio body class.

Any tips on changing this would be most welcome! Thanks!