There are some people who think that Toolbar icons and Brushed Metal Window absolutely doesn’t go together, I do agree with them but after some playing with toolbar icons for my client’s upcoming application, it’s possible for them to look good together by changing the shadow setting. Instead of using standard floor shadow, I used back shadow to help create a depth between icon and Brushed Metal Window.
Another way would be insetting them like Safari’s toolbar controls but it will not works for some icons such as Manage Filters icon on Fig. 1.
Apple should address this problem in their Human Interface Guidelines if they’re going to leave Toolbar support for Brushed Metal Window.