Background and Objective Green is the hot word today. All the efforts to minimize Green House Effect and thus keep the environment green for our generations to come; comes under the term Green today. So, how a lightning solution makes a building green or otherwise? It is related to the energy consumption of the lighting solution. Let us take the example of an incandescent bulb. It consumes electrical energy to give light and the electrical energy it consumes comes from thermal power plants which burn fossil fuels and produce greenhouse gases – CO 2 , NO x , etc. The conversion of electrical energy to light is never 100%; instead, part of the electrical energy is converted to ultraviolet and infrared radiation as well and these radiations are not useful as far as a lightning solution is concerned. So that part of the electrical energy is literally wasted. Now better is the efficiency of electricity to light conversion, lesser is the electrical energy wasted and lesser is the amount of fossil fuel burnt and greenhouse gases produced to get the same amount of light. This essentially leads to the fact that a lightning source with greater efficiency is the best lighting solution for a green building. In light of this background, the main question guiding these experiments was to determine the spectral efficiency of different light sources like an incandescent lamp, fluorescent lamp (CFL), and Light Emitting Diodes (LEDs) of different colors (Blue, Orange, and Red). Safety Considerations The experiment involved required handling electro-optical appliances like different light sources. Therefore, all the precautions related to the handling of electrical appliances were adhered to. As an electrical safety shoe was used, all the electrical points and appliances were handled carefully. To protect the eye from ultraviolet (UV) rays UV protection glasses were used. To ensure the safety of the equipment the spectrometer was used as per the laid down procedures. Procedures and Tests In line with the main objective of this experiment spectrum of the five different light sources namely incandescent lamp, fluorescent lamp (CFL), and Light Emitting Diodes (LEDs) of different colors (Blue, Orange, and Red) was recorded using Ocean Optics Spectrometer one after another. Distance between the light source and the spectrometer was kept the same for all the different light sources. Data, Calculations, and Representations The electromagnetic spectrum of different light sources was recorded. This spectrum is presented in figure 1, below: It can be seen from this spectrum that the spectrum of the incandescent lamp is very wide, spread over the almost entire optical spectrum, and has a single peak. The fluorescent lamp has many peaks in its spectrum and the majority of the peaks lie in the optical spectrum. Different colored LEDs have peaks in respective wavelength regions like Blue LED near 450 nm, Orange LED near 600 nm and Red LED near 650 nm. The Energy Spectrum of different light sources is presented in figure 1, below: This spectrum is also very similar to the spectrum in figure 1 with the difference that the left tail of the curve is raised upwards and the right tail is