If black is the absence of light?

Question

than white must be the presence of light

but black and white are called colours (why?)

Answer 1

It has to do with what light reaches our eyes after being reflected off an object.  A whit object reflects all light thereby causing all colors of the spectrum to enter our eyes and we perceive it as white.  A black object absorbs all colors and does not allow light to reflect into our eyes.

Different colored objects appear to be that color because they reflect that color aspect of the spectrum into our eyes.

Answer 2

Colours are merely what we have defined certain wavelengths on on the electromagnetic (em) spectrum to be. We define white and black as objects that do the following:

White - emission of all wavelengths of visible em radiation.

Black - absorption of all radiation in the visible spectrum and radiation of energy in non visible forms (e.g. in the infra red region)

Answer 3

Black is the presence of all color and white is the absence of all color.

Answer 4

I could get a violation email if I answered this.

Answer 5

White light is the combination of all the colors on the visible spectrum. Black and White are called colors because they can be seen with the naked eye.

Answer 6

They are called colours as they can been seen with the naked eye. You are correct in saying black is the absence of light, whilst white is the presence of light.  Other than that i don't know why they would be colours. Maybe to make it easier for everyone?

Answer 7

Actually they are not called colors.  You are correct in your definition.