“Gray-bar” is an SEO insider term used to describe what happens when Google bans your site and takes away your page rank. The term itself is referring to the color of the Google PageRank indicator bar that resides on the Google Toolbar, available at http://toolbar.google.com.

The background color of the bar should be white with an amount of green in it showing your PR, much like a horizontal thermometer reading. If the green fills 40% of the bar, your page has a PR of 4. Don’t worry if you’re not good at estimating horizontal thermometers. You can simply let your mouse hover over the PR bar and a tool tip will show the PageRank value or you can use the Google PR tool avaiable right here.

If the bar is all white, this means your page currently doesn’t have any accumulated PR. However, a gray bar is usually a good indicator that your page has been banned for some reason, such as employing Black hat SEO techniques. But don’t panic just yet. We’re told that on a couple occasions multiple pages have shown up gray-barred simply because a change was happening on Google’s end or the bar was just “buggy” at that time. Their rank – complete with green and white colors returned the next day.