The goal of the current studies is to explore the conditions by which light color temperature impacts cognitive abilities and the development of this relationship. Experiments 1 and 1A explored whether exposure to light fluctuating around a central color temperature leads to increases in attention in adult participants. Results showed that, under the dynamic lighting condition, participants’ showed a significant decrease in reaction time on a measure of sustained attention, beyond those of a static light source at a cooler color temperature. Experiment 2 tested whether preschool-aged and 7-year-old participants would show increases in attention and cognitive flexibility after exposure to light set to a cooler color temperature, as has been previously seen in older children and adults. While 7-year-olds showed no effect of the lighting condition, preschool-aged children exposed to cooler color temperature light showed significantly greater improvements in cognitive flexibility than controls, demonstrating that the relationship between light and cognition is present from an early age. Taken together, these studies add to the growing literature demonstrating that the spectral composition of light can lead to improvements in cognitive abilities.