The theme itself is very interesting, yet there seems to be some problem when using with nightly 133.0a1 Once the firefox is closed the next time it opens the colour theme only pop up for a second then disappear. This happened when using 'always inprivate' as well as normal tabs (I have select the add-on to working while inprivate mode) . I wounder if there is a bad setting or some problem when using with nightly.