URLColors is a Chrome extension that allows you to flag specified websites by highlighting the website with a custom colored border.

The best part of this extension is the option to customize the width and color of the border. It has a demo mode that allows you to set the amount of time the extension will go into sleep mode, and a snooze mode.

There are a number of options to make the URLColors extension work for you.

There are a few different categories of websites. If you choose "all sites" it will highlight every URL on the site. If you choose "http" it will highlight any URL starting with "http." If you choose "mysite.com" it will highlight the website mysite.com. If you choose "domain.com" it will highlight the domain.com website. The website you choose to highlight will be the one that is highlighted.

URLColors also has the option to add a keyword to match against the tab url.