Leaders of the U.S. Naval Academy tinkered with the composition of the color guard that appeared at a World Series game last month so the group would not be exclusively white and male. ...Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, elevated diversity to a "strategic imperative" during his tenure as chief of naval operations. Academy leaders, on their official Web site, call diversity "our highest personnel priority."That thinking reflects "a sea change, in that this initiative was generated from within the military, rather than imposed from without by civilian overseers," said retired Marine Maj. Gen. Thomas Wilkerson, an academy alumnus and chief executive of the U.S. Naval Institute, an independent think tank. Some alumni, he said, "have voiced concerns that it will happen at the expense of quality and combat readiness."A military-oriented blog, CDR Salamander, reported last week that two white men had been pulled from the color guard that went to Yankee Stadium and replaced with an Asian American man and a white woman to make the group more diverseAcademy leadership disputed that account."No midshipman was ever given approval to attend this event and then later told they could not," said Capt. Matthew Klunder, commandant of midshipmen, in a statement Monday. He said he considered replacing two white men but chose to expand the color guard from six to eight to make it more representative of the Naval Academy.Two of the eight could not perform because Zishan Hameed, one of the midshipmen added to the color guard, had forgotten parts of his uniform, Klunder said. The color guard marches in pairs.