How to style membership protected menu item?

I searched, but couldn't find tips for what I'm trying to do...

Does anyone have suggestions for styling a membership protected menu item differently than others? We have various tabs in our navigation menu and are hiding one from all visitors. When members are logged in we would like that tab to stand out. Even just changing the text color would suffice, but altering the background, etc. would be a bonus. Any attempts to edit the style of the menu item result in changing the style of all tabs.

The menu can be seen at http://agreda.com/ but of course you will not see the hidden tab, which is displayed using the following code:
<li id="menu-item-1408" class="menu-item menu-item-type-post_type menu-item-object-page">
The class is shared by all other menu items, so I'm not sure what to edit to make this specific one stand out, if it is possible. Thanks in advance for any feedback