Effects are a setting in the Hue app that let your lights mimic things from the natural world: the gentle glow of candlelight or a roaring fireplace, for example. Best displayed on gradient lights, effects work on any compatible Philips Hue light. Effects don't work on older generations of Philips Hue lights as those products don't have the hardware needed to support the feature. Additionally, some effects don't work on White bulbs.