When you say wether white or black is a color if depend what you are refering to. First white light consist of all the UV frequencies ranging from 350 to 750 nm that we are capable of detecing with our eyes. Differnt sources of light emit differnt frequencies. For example, the sun not onlys emits from 350 750 nm range but it also emits Ultra violet radiation as you know from 10 - 400-nm in the UV spectrum. When you look at an object you are actually seeing the light that is not absorbed by that object. Lets take for example a white and black piece of paper. The white piece paper is compoesed of bascically C,H, O. These elements are not capable or absorbing light due to the piece of paper molecular structure. So what your actually seeing is the light that is not being absorbed. Light is absorbed through conjugation (which is alternating double bonds). Depending on the conjugation of an object depends on what light frequencies it is capable of absorbing. This does not apply to everthing for example perylene (a form of dye) gets a little complicated from here. Just ask if you want to know why Didn't go into much detail in my explanation requires a background in organic chem and a little of insturmental analysis.