The most famous "blue man" -- known as "Papa Smurf" -- has died.
Paul Karason was born a fair-skinned, freckled boy with reddish blond hair. But later, he developed skin with a bluish tinge against his shock of white hair, the result of a rare medical syndrome known as argyria or silver poisoning from dietary supplements.
Karason died at the age of 62 this week after being treated for pneumonia at a Washington hospital after having suffered a heart attack. He'd also previously had a severe stroke, his estranged wife Jo Anna Karason told NBC's Today.
ABCNews.com interviewed Karason in 2008. At the time he lived in Oregon. He said the blue tinge had started more than a decade before that when he saw an ad in a new-age magazine promising health and rejuvenation through colloidal silver. He drank about 10 ounces a day of the home-brew that he dissolved in water.
Karason said he hadn't even realized his skin had turned a shade of blue until an old friend came to visit.
"And he looks at me and he says, 'What have you got on your face?' 'I don't have anything on my face!'" Karason said. "He says, 'Well, it looks like you've got camouflage makeup on or something.' And by golly, he came in and he was very fair-skinned, as I used to be. And that's when it hit me."
In those first months, he didn't notice a change in his skin color. But there were changes in his health.
"The acid reflux problem I'd been having just went away completely," he said. "I had arthritis in my shoulders so bad I couldn't pull a T-shirt off. And the next thing I knew, it was just gone."
As for whether it was the colloidal silver that had cured him, Karason said, "there's not the slightest doubt in my mind." As recently as the 1950s, colloidal silver was a common remedy for colds and allergies.
Karason became an Internet sensation, as were many others who have blue-shaded skin. The most notorious -- the Blue Fugates of Kentucky -- lived in an isolated pocket of Appalachia, passing down a recessive gene that turned their skin blue. Doctors don't see much of the rare blood disorder today.
Their ancestral line began six generations earlier with a French orphan, Martin Fugate, who settled in Eastern Kentucky.
Then there was Kerry Green , a "blue baby" born in 1964 in Tulsa, Okla. His family was given little hope that he would live because of a malformed aorta. But by 3 years old and several heart surgeries later, Green was being described by doctors as a "miracle child," small for his age at 23 pounds, but a "real live wire."
What doctors didn't know then was that the boy had a more serious underlying condition, a rare blood condition called methemoglobinemia -- the same disorder that affected the Blue Fugates of Kentucky.
"I was picked on as a kid in elementary school because I am blue," said Green. "I look dead. My lips are purple and my fingernails and toes are dark."
At the time, Green lived in Seattle and was disabled, but he said he believed finding a genetic connection to the Fugates might help him learn more about the father he never knew.
"I am positive my father had the condition," said Green. "I did see one kind of blurry picture of him and you could almost see it. He's got the pale look I do."
Bob Green, who would be about 74, had been a long-haul truck driver with relatives who had migrated west from Tennessee.