Clicking on the Status of a task will bring up the list of statuses, which you can customise.

You can create up to eight custom statuses, including changing the default ‘In progress’, ‘Complete’, and ‘Paused’ statuses. Type next to the coloured tabs and click ‘Save’ to update your statuses.

Your custom status will now appear in the status drop-down across all tasks on that specific project. Customised statuses are unique to each project.