This article explains in detail new research that explores how the colour of light effects our cognitive performance.  Kyungah Choi and Hyeon-Jeong Suk who performed the study identified that there is a limit to how intense classroom lighting can be before it starts to disrupt the performance of the students.   We have seen studies in the past highlight that exposure to regular patterns of light and dark regulates our circadian rhythm and when disrupted we see an increase in some health conditions such as obesity and diabetes so it makes sense that it would also effect our ability to concentrate.  I'm relieved schools and organisations are investing in better lighting but also investing in better health for their students and employees.