When the environment changes, the visual system adjusts to maintain accurate color perception. Such adaptations happen at different time scales, and long-term effects are of particular interest because they may engage mechanisms of long-lasting neural plasticity. Long-term adaptation to changes in the color of the environment produce strong and long-lasting changes in color perception, with the general effect of neutralizing the dominant color. Large individual differences and details of the time course are currently unexplained, and the limits of adaptation remain unexplored. Experience with an environment appears to allow observers to adapt more strongly and quickly to it. Long-term color adaptation may serve as a model system for understanding general mechanisms of neural plasticity, including those relevant for therapies for visual disorders.