Most ran in T-shirts and running shorts, although some came clad in less traditional get-ups -- a wedding dress, a neon unitard, a penguin costume, a unicorn costume.
Tutus were a popular accessory.
So were crazy socks and silly headgear.
And while most of the outfits started out white, they didn't stay that way for very long.
The whole point of the Run or Dye 5K walk/run Saturday morning at the Benton County fairgrounds was to get messy.
People had no trouble embracing that.
They pelted each other with packets of brightly colored dye. And they were pelted by others as they negotiated the course.
"They had four stations throughout the race, and they hit us with four different colors," said Shelley Ellis, 31, of Kennewick, after she crossed the finish line. She was covered head to toe in dye -- not a speck of white left on her once-white tank top.
Almost everyone around her was covered, too, with dye all over their clothes, limbs, shoes and hair.
Marilou Fernandez and her crew of family and friends were covered before they even set foot on the course. They prepared by tearing open dye packets and dousing each other. And they had no plans to avoid the dye blasts as they ran, either.
"Oh now, we're going to run right into it," Fernandez, 37, of Pasco, told the Herald.
"This is my trophy," friend Candy Jones of Richland piped in, pointing to her dyed T-shirt.
The Utah-based company Viral Events hosted the 5K, which drew between 5,500 and 6,500 people, an organizer said Saturday. The company has staged several other similar events around the country, and many more are planned this year from California to New York.
They take inspiration from the Hindu festival of Holi, known as a festival of colors.
As runners got ready Saturday, several said they were drawn by the chance to cut loose and have a good time with friends and neighbors.
Jenn Nelson of Kennewick and her daughter Dahlia, 4, signed up with a group of family and friends. They wore handmade multi-colored tutus.
"She's excited," Nelson said, nodding at her daughter. "She's got her little packet of dye. I told her, 'Anytime during the race you can throw dye at Mommy,' which she thinks is just wonderful."
The dye used during the event was washable, with a cornstarch base, so Nelson and everyone else didn't have to worry about whether it would scrub off. Viral Events also submitted a cleanup plan for the grounds, an official from the Horse Heaven Events Center at the fairgrounds told the Herald last week.
Part of the profits from Saturday's event will go to the YMCA of the Greater Tri-Cities.
As runners crossed the finish line, they guzzled water and headed to a stage, where music played. After a countdown, dozens of them tossed more dye into the air, creating bright clouds that rained color.
MaryJo Boyus, 32, of Richland, said she hopes the colorful 5K event will become an annual tradition in the Tri-Cities. In her view, she said, "it's an excuse to be crazy, colorful and just have fun."
-- Sara Schilling: 582-1529; email@example.com; Twitter: @saraTCHeraldS