Value is the lightness or darkness of a color.
Not all hues in the spectrum have the same value.
Yellow is the lightest value, and purple is the darkest.
The value of a hue (color) can be changed by adding white or black.
Saturation refers to the brightness and dullness of color.
A saturated color is extremely bright (the brightest hues are the three primary colors).
An unsaturated color is extremely dull.
When any two colors are mixed together the results are always duller than the "parent" colors.