i need an example of a color triad.?

Answer 1

I would only add to Georgia's answer by adding that the Triad's triangle is an equilateral one. Red - Yellow - Blue for one, Violet - Green - Orange, or any other combination on the colour wheel that forms this equilateral triangle.

http://en.wikipedia.org/wiki/RYB_color_model

Answer 2

A color triad are three colors on the color wheel that form a triangle. So purple, orange and green would be one. Or red, blue and yellow.