The attack reportedly happened as the leading Kremlin critic and anti-corruption campaigner stopped to shake a man's hand in the Siberian city of Barnaul.
The green liquid used in the attack is a common Russian antiseptic, which remains on skin for days but is otherwise harmless.
Navalny appeared to take the attack in his stride, tweeting: "I will be opening a headquarters in Barnaul as if I'm from the film The Mask! Cool. Even my teeth are green!"
The tweet was a reference to the Hollywood film "The Mask," in which Jim Carrey played a superhero who wore a green mask.
The anti-Putin campaigner was in Barnaul to open his headquarters in the city as part of his campaign to stand in Russia's 2018 presidential elections.
He is currently unable to stand for election due to a criminal conviction for fraud, but his supporters say the charges against him are politically motivated.
|Russian opposition leader Alexei Navalny takes a selfie with supporters after he said an unknown attacker sprayed a bright green antiseptic on his face. (Alexei Navalny via AP)|
Leading Putin critic Russian politician Alexei Navalny is attacked with green dye leaving him looking like Jim Carrey in The Mask
One of Vladimir Putin's biggest critics, Russian politician Alexei Navalny, has had bright green liquid thrown over him during a visit to Siberia.
Navalny, who wants to stand against Putin in next year's presidential elections, laughed off the attack today, tweeting: 'I will be opening a headquarters in Barnaul as if I am from the film The Mask! Cool. Even my teeth are green!'
In the Hollywood film Jim Carrey stars as timid clerk, Stanley Ipkiss, who transforms himself into a belligerent superhero when he dons a special green mask with magical powers.
The green liquid sprayed in Navalny's face has been identified as a common Russian antiseptic which remains on the skin for days but will eventually wash off.
The mystery assailant sprayed it on him when he went to shake the man's hand and then fled in the confusion.
Kevin Rathrock, web editor of the Moscow Times, later tweeted: 'Navalny’s sister in law and nephew have painted their faces green in solidarity. I smell the beginnings of a whole movement.'
Navalny, 40, is travelling around Russia opening campaign headquarters although a criminal conviction for fraud bars him from running in next year's election.
His supporters claim the charges were politically motivated.
He is widely followed on social media and in 2011 he urged people to vote for anyone but Putin's United Russia, which he called the 'party of crooks and thieves', a term that has stuck, much to Putin's chagrin.
Navalny was jailed in July 2013 for embezzlement in the city of Kirov but few independent observers believe the trial was untainted by political bias.
Anti-Putin Russian presidential candidate Alexei Navalny attacked with green dye
It isn’t easy being green, but Russia’s opposition leader is trying to make the best of it.
Presidential candidate Alexei Navalny was doused with the dye Brilliant Green by an unknown assailant as he was campaigning in the Siberian city of Barnaul on Monday.
The solution, known as “zelyonka” in Russia, can take days to fully wash off, though the crusader against corruption in Vladimir Putin’s Kremlin didn’t get blue after being attacked.
Navalny appeared with his new visage in a video message, and said that his resemblance to The Mask, Shrek, the Incredible Hulk or a character from Avatar would not stop campaigning.
The candidate’s supporters have also taken to social media in solidarity, posting pictures with their faces painted in various shades of green.
Navalny, who helped lead mass protests against Putin in the winter of 2011, is unlikely to beat him or a member of his ruling party in Russia’s 2018 election.
He is technically barred from running because of a fraud conviction in a case that many believe is politically motivated, and will receive little support from state-run media.
However, the 40-year-old lawyer has a large online following interested in his anti-corruption investigations, including a report released earlier this month alleging that Prime Minister Dmitry Medvedev has amassed a secret empire of real estate wealth through connections to other top officials.