Very good. All I needed was a place holder for dark mode. In settings, under More.

placeholderBackground url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAAAAACoWZBhAAAAJElEQVQI12PUYWZgYGD4y8DAwMLMxAAFcAYRTJa/DDATCKoFANCbA0M7UjZFAAAAAElFTkSuQmCC") repeat scroll #fff

Просто супер!

This is my favorite extension. Extremely powerful once you understand how to use it.

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6xStars_needed!

Literally the BEST security addon for Firefox after NoScript, with almost the same level of power and control.

Chromeの方でサポートを打ち切るとあるので選択肢を考えます。

It's a shame development has halted. However, the same functionality can be found in uBlock Origin, by the same developer, and it's actively maintained. But I find uMatrix UI is better than uBO.