The Firefly night sight, may appear dull in color and will require charging before use. The yellow and green spectrum base colors will change color slightly as they are exposed to a strong light source while charging. For the first charge, it is recommended to allow the sight to charge for at least five minutes. Any time the glow appears to diminish in strength, a 2-second hit with a tactical light will bring back the glow. A freshly charged Firefly will spike very bright, and then settle down to maintain a plateaued glow for many hours. The glow becomes increasingly more apparent as the environment becomes darker.