Around 10,000 visitors enjoyed the Holi Festivals of Colours in Cologne on Saturday in which tonnes of powdered dye was thrown in the air to celebrate an Indian festival.
But revellers took to Facebook afterwards to complain that the coloured particles would not wash out after it mixed with rainwater, the Westdeutsche Allgemeine Zeitung (WAZ) newspaper said.
One wrote: "I still look like a clown." Another said: "My hair is still pink and green." One wrote sarcastically: "Wonderful when you've got to meet customers two days later."
And those struggling to wash the dye from their hair, skin and clothes have come up with unusually tricks to get rid of the colour. One recommended using asprin, another advised trying face wash.
A spokesman for the festival told WAZ that the colours were water soluble and should wash out. "The colours do not have the chemical properties to dye hair permanently," the spokesman said.
Organizers said people should wash their hair several times to get rid of the dye and posted tips on their website.