The Anarchist flag is reliable black or purple-and-black; it symbolizes resistance in opposition to authoritarianism

https://blogfreely.net/brynneeasm/the-right-to-raise-the-stars-and-stripes-and-what-it-says-about-freedom

The Anarchist flag is reliable black or pink-and-black; it symbolizes resistance in opposition t authoritarianism and has roots in more than a few social pursuits right through history advocating for freedom from oppressive governments.