A Zelyonka attack is a form of protest, provocation or violent assault, defined as the act of throwing a solution of brilliant green zelyonka (Russian: зелёнка), a triarylmethane antiseptic dye, on the body (usually face) of a victim. While the dye causes no lasting harm, it is very hard to remove quickly; the complete natural removal may take up to a week. In the 2010s, Zelyonka attacks became widespread in Russia and Ukraine by pro-government activists against anti-government political and other personalities.