People take part in The Color Run in Brussels, Belgium September 6, 2015. The Color Run is a five-kilometre, untimed race, held in cities worldwide, with the aim of promoting healthy living. Participants are doused from head to toe in different colors at each kilometre. (Photo by Yves Herman/Reuters)

People take part in the Cupid's Undie Run in the Manhattan borough of New York February 7, 2015. The run, held to raise funds to combat children's tumors, sees runners in their underwear partying and running along the West Side Highway. (Photo by Carlo Allegri/Reuters)

A charity runner dressed as Father Christmas steps out of a portable toilet ahead of the “Santa Run” charity fun run in Stockholm on December 10, 2017. Hundreds of participants dressed in Santa suits and wearing white beards ran through the streets of the old town in Stockholm in an all charity run. (Photo by Jonathan Nackstrand/AFP Photo)

A seven-week-old Persian kitten peers into a goldfish bowl, 9th October 1972. (Photo by William Vanderson/Fox Photos/Hulton Archive/Getty Images)

Participants are covered by colored powder as they compete in The Color Run, a five-kilometre untimed race, in Hanoi, Vietnam September 26, 2015. Approximately 7,000 participants took part in Hanoi's first Color Run, reported local media. (Photo by Reuters/Kham)

Participants try to cover themselves from color powder sprayed by volunteers as they run through a “color station” during a five-kilometer color run event held in Beijing, China Saturday, June 21, 2014. (Photo by Andy Wong/AP Photo)