NEW YORK (AP) — Graham Nash blames bad colors for Crosby, Stills and Nash’s off-key performance during the National Christmas Tree lighting in Washington last month. Nash says all the musicians involved in the show used color-coded microphones in sound check, but the microphones were mixed up when it came time for the show. Nash says the technicians at the sound board couldn’t figure out who had which microphone, and the members of CSN couldn’t hear each other. Nash says CSN weren’t at their best anyway. He says the producers of the show apologized to them, and “if we did one lousy show in our lives, so be it.”