are black and white colors, or just shades?

Hello fuct1--

I have carefully researched your question and have your answer.

First, I searched the definition of the word "white." I used the
following search terms: define:white

You may view the results of my search online. The link is
://www.google.com/search?q=define:white

In this search, I learned that the definition of "white" is "the
quality or state of the achromatic color of greatest lightness."
Therefore, white is a color not just a shade.

Next, I searched the definition of the word "black." I used the
following search terms: define:black

You may view the results of my search online. The link is
://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=define%3Ablack

In this search, I learned that the definition of "black" is the
quality or state of the achromatic color of least lightness."
Therefore, black is a color, not just a shade.

I also conducted searches for the words "color" and "shade" just to
clarify the difference.

The links are:

Color: ://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=define%3Acolor

Shade: ://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=define%3Ashade

The definition of color is: "a visual attribute of things that results
from the light they emit or transmit or reflect; "a white color is
made up of many different wavelengths of light""

The definition of shade is: "a quality of a given color that differs
slightly from a primary color; "after several trials he mixed the
shade of pink that she wanted""

Therefore, we can deduct that all shades are in fact colors. 

I hope this helps. If you need any further information or any
clarification, please don't hesitate to click the "clarify" button.

Thanks,

darrel-ga

The answer to the question of whether white and black are colors
depends upon how you define the word "color."

"When all the wavelengths of the visible light spectrum strike your
eye at the same time, white is perceived. Thus, visible light is
sometimes referred to as white light. Technically speaking, white is
not a color at all, but rather the combination of all the colors of
the visible light spectrum. If all the wavelengths of the visible
light spectrum give the appearance of white, then none of the
wavelengths would lead to the appearance of black. Once more, black is
not actually a color. Technically speaking, black is merely the
absence of the wavelengths of the visible light spectrum."

http://www.physicsclassroom.com/Class/light/U12L2a.html