The discussion centers on the causes of the green color observed in a photographed meteor, with participants suggesting various elements like copper, nickel, and barium as potential contributors. Atomic oxygen is highlighted as a likely cause due to its specific emission line at 557.7 nm. The presence of nickel in meteorites is noted, as it is commonly found in significant quantities. Participants also mention that atmospheric conditions and camera settings could affect the perceived color in the photograph. Overall, the consensus leans towards a combination of meteor material and atmospheric factors contributing to the green hue.