Right-click on one of those tabs, select 'Add Tab to Group' in the drop-down menu, and then type the group name and select the color you want the group organized by. It essentially lets you organize your tabs like a color-coded filing system.
Called Tab Groups, the feature allows you to group tabs together and organize them by color, custom group name or even an emoji. Google introduced a tab grouping feature to Chrome within the past year that is a life saver if you're somebody who always has a zillion tabs open at a time. This is another pro tip rather than a setting to change, but it's incredibly useful.
