It is a good plugin in concept and does what it says and has 4 modes which one way or the other make sites work with dark color profiles.

Alas! In many instances, especially sites with a lot of media or large animated pictures, it makes my browser either slow to a crawl or completely locked up for many seconds. Opening many tabs in short stints becomes a nightmare in such cases.

Especially when it first got installed (I had about 12 tabs open), it locked up my browser for more than a minute.