The online status is being displayed based on the timecards created, so it should be updated after reviewing timecards in your logbook.
In your dashboard, you should be able to see your status right next to your picture. You can also place your mouse on top of any picture, this will bring more details about the contractor's status.
Green - This means that there were timecards uploaded in the last 10 minutes.
Orange/Yellow - It means that there were timecards uploaded in the last hour, but not in the last 10 minutes.
Grey - That means there were no timecards uploaded in the last hour, it will include also the amount of time since the last timecard was uploaded.