All I can find is this, from an article about Spikey Mikey's and David Corn's Book:
Richard Armitage was clearly agitated. As recounted in a new book, "Hubris: The Inside Story of Spin, Scandal, and the Selling of the Iraq War," Armitage had been at home reading the newspaper and had come across a column by journalist Robert Novak. Months earlier, Novak had caused a huge stir when he revealed that Valerie Plame, wife of Iraq-war critic Joseph Wilson, was a CIA officer. Ever since, Washington had been trying to find out who leaked the information to Novak. The columnist himself had kept quiet. But now, in a second column, Novak provided a tantalizing clue: his primary source, he wrote, was a "senior administration official" who was "not a partisan gunslinger." Armitage was shaken. After reading the column, he knew immediately who the leaker was. On the phone with Powell that morning, Armitage was "in deep distress," says a source directly familiar with the conversation who asked not to be identified because of legal sensitivities. "I'm sure he's talking about me."
And your gonna believe Armitage, a known leaker, over Colin Powell? He probably did tell Powell, but Armitage would be the last person to believe over Colin.