Awesome add-on! So close to being perfect. A few suggestions are add a "Private Window" container that as is expected is segregates from all the other containers and whose history does not get kept at all. Another suggestion is allowing for each container category to have custom Firefox privacy settings. Also if we wanna get crazy maybe allow containers to be tied to VPN connections via the user's VPN service preferrence. Final suggestion is MORE COLORS for container icons. Nonetheless this is a great add on!