Value is the relative lightness or darkness of a color. Value is generally controlled most directly by the addition of black or white. Adding black creates different tones of a color while adding white creates a range of tints. Care must be taken when adding black to lower the value of a color because this procedure can also dramatically shift the hue. This is especially apparent when attempting to create tones of yellow. Adding black not only decreases the value but also usually shifts the hue towards green.
