Light perception happens in a paper thin layer of cells called the retina.
Light detecting cells are cones and rods.
You cant see colors in the dark because the rod cells in your retina take over in low light.
The first step to understanding the phenomenon of color is to think about it as a wave.
We call the repetitive motion of a wave a periodic motion.
When you are measuring the period of a wave you are measuring how long it takes for a wave to go through a full range of motion.
White objects will reflect all colors of light and black objects will absorb them.
Color spectrem (2015) Uploaded by windows. Available online @ http://msdn.microsoft.com/en-us/library/windows/desktop/dd372201(v=vs.85).aspx