Light emission characteristics of a white light source are often expressed by a “color temperature” and is measured in K (Kelvin). If you have been exposed to indoor or studio photography you will know that a 5000K lamp will get you close to natural daylight.
Office and a classroom environment often have similarities as they are places where a lot of reading and evaluation of physical items are required. It has been proven that light sources nearer to daylight give higher contrast on printed matter and therefore make it easier to read longer with less fatigue.
Many organizations arbitrarily chose 4100K because a bright white fluorescent tube has about that color temperature, this has to do with the phosphors that convert UV light from the gas discharge tube into visible light and happens to be that 4100K producing phosphors are the lowest cost to produce for the fluorescent tube manufacturers, it also helps GE and others to create a specification that produces sort of dirty white light and is outside the real daylight spectrum.