Passing observation on colour perception 

Tonight, checking on the redecorated walls of the room, I noticed that my eyes perceived a much sharper differentiation between  the shades of white on the walls (chalky emulsion of Chinese white) and the ceiling plus woodwork (brilliant  white) under artificial light (LED bulb rated at 2700 Kelvin)  compared to viewing under daylight, where the colour temperature would be at least 5000 K if it is a warm sunny day, and colder on cloudy weather.