I agree with most others here, that's the way I'm hoping it will work in a future version.
Pure notifications like "Rank X achieved" could be marked as read the instant they are displayed on screen. A typical user will have only one at a time in their Notification menu, maybe two.
But power users may have 30 notifications on any single day, and most expect to use that Notification menu as their to do list. IMO, the notification should change color when the item is read, whether you've clicked it in the Notification menu, or read it some other way. So if I go back to my notification menu and see only 14 bright notification, I know that I've already read the 16 other items.