If the current page is in a container, the Open link in New Tab item changes to Open link in New ContainerName Tab. Right-click on any link, select Open link in New Container Tab, and then select the desired container. You can open links in a new or different container. Click the menu button and select Settings. Click the menu button and select Options Preferences. In the Menu bar at the top of the screen, click Firefox and select Preferences. You can open the Container Tabs settings panel as follows:
You can also add, remove or edit containers from the about:preferences#containers settings panel for Container Tabs: When you click the Edit Containers or the + buttons, you can change the color or icon associated with a container or change the container name.
You can create, delete, and edit containers from the Containers menu.