Thanks for the feedback!

Unfortunately, this issue is a bug/defect within Firefox itself and is unrelated to the add-on (see https://bugzilla.mozilla.org/show_bug.cgi?id=1488384). This bug report is marked as closed but there are still reports of it occurring for users.

There are a couple of work arounds being suggested that may fix the issue for you depending on which version of FF you're on and which OS (Windows, Mac, etc) you use. The most common one seems to be:

1. enter "about:config" (without quotes) in your address bar and press enter

2. click the "I accept the risks" prompt

3. in the search field paste "browser.in-content.dark-mode" (without quotes). if the result lists "false" under the "Value" column, right-click on it and select "Toggle".

4. Then, quit FF completely and re-open.

5. I tested this again on my current setup (Mac OSX 10.13 with native Dark Mode, FF 69.0.3 with native Dark Mode and this addon installed) and the issue is reduced significantly.

If you can, give this a try and let me know how it works.

The only other option that I've found which completely resolves the issue for me was to move to Firefox's beta build (a.k.a. Firefox Nightly). The issue appears to be fixed in this build but for many users, the instability of the beta build and it being updated every night isn't worth the hassle. Personally, I have found it relatively smooth and well worth trade-off as I too could not stand the white-flash issue.


Regards,

Dan