Colour Theory- Hue, Value and Chroma

Hue
Hue is the term for the pure spectrum colors commonly referred to by the "color names" - red, orange, yellow, blue, green violet.

Value 
Value is defined as the relative lightness or darkness of a color. Adding white to the colour creates a tint and adding black creates a shade

Chroma
are related but distinct concepts referring to the perceived intensity of a specific colour. Chroma is the degree of difference between a color and gray. 

References http://en.wikipedia.org/wiki/Colorfulness- http://char.txa.cornell.edu/language/element/color/color.htm