The 28-year-old has posted a video on social media, confessing he was initially stunned by the health news, but now he's very sick.
"I consider myself pretty healthy," he said. "I work out regularly, I eat healthy. I became symptomatic a few days ago, got my test results back today and they are positive..."
"It's (COVID-19 virus) been kicking my a** just to put it very bluntly. For those wondering what my symptoms are: headache, body aches, night sweats, fever, shortness of breath and a cough. Currently I get winded doing simple tasks, like walking up the stairs (or) getting out of bed."
Colton revealed he went public with his diagnosis to "hopefully encourage you guys to stay home, do your part, take care of yourselves, take care of one another."
Meanwhile, British TV personality Fiona Phillips has confirmed she has also tested positive, in a Twitter post on Friday, March 20.
"I am in bed with #coronvirusuk (sic)," she wrote. "It's not a very pleasant bedfellow, but nothing more than sore throat, dry cough, headache & tiredness. As long as it stays that way... DON'T panic!"
And U.S. TV favourite Andy Cohen has also revealed he's fighting the virus.
"After a few days of self-quarantine, and not feeling great, I have tested positive for Coronavirus," the "Watch What Happens Live" host wrote on Instagram on Friday.
"As much as I felt like I could push through whatever I was feeling to do #WWHL from home, we're putting a pin in that for now so I can focus on getting better. I want to thank all the medical professionals who are working tirelessly for all of us, and urge everybody to stay home and take care of themselves."
The trio joins the likes of Tom Hanks, Rita Wilson, Olga Kurylenko, "Game of Thrones" stars Indira Varma and Kristofer Hivju, "Frozen II" star Rachel Matthews, singer Charlotte Lawrence, and "Lost" actor Daniel Dae Kim, who are all battling the virus in quarantine.
Meanwhile, Idris Elba, who confirmed he had contracted the virus earlier this week (begin March 16), jumped on social media on Friday to deny reports he is in critical condition following hoax video claims.
When a fan informed him of the story, Elba insisted it wasn't true, adding he still hasn't shown symptoms for coronavirus.
"This is fake," he said. "I'm fine for now. Thanks for showing me."
Asked if he had been sick, the "Luther" star responded, "I really didn't have poorly days... I had a headache and body aches on the day I tested but that's been it."