OK, next thing to know about color is a quality called saturation. Saturation can be thought of as how much the color is diluted with white. If I took yellow paint and mixed in white (or black) paint, then I would get less and less vibrant yellows. How much saturation is "natural" is a matter of individual eyesight. Usually, we tend to like photographs with at least some colors more saturated than in reality. Saturation is used to greatest effect in marketing where strong bright colors will draw attention long enough for a slogan to be read. In the photo above no explanation is necessary, from left to right saturation goes from high to zero.
