When light falls on any object it reflects back the color of light that the object represents, White light is comprised of red, blue and green color .Similarly white color is the combination of red blue and green dyes, pertaining to this fact if a light is directed on an unknown color X the light it will reflect back will be the same as its color ,So if we shine a red light individually on the color ,the light it will reflect back will be proportional to the intensity of red color in the object.We have made a sensor that houses three compartment with isolated the sample from ambient light and shines Red ,Blue and Green colored light individually .It also measures the light intensity response by using an LDR.