Colors in a photograph can affect the mood of a scene and how we interpret it. They can be described as calming, exciting, placid, bright, brilliant, or dull. Well positioned within a frame, the colors alter how the photograph is perceived. Furthermore, they can be enhanced through saturation, hue, and luminance. This allows the photographer to change the characteristics of individual colors to strengthen the composition. In addition, the "raw" digital photograph that begins in color, can be converted to Black and White by removing the colors and adjusting the luminosity values, but that is an entirely different discussion.
A Master photographer must know the way colors interact with the audiences eyes. Any adjustment in the intensity of light brings about a shift in color and how it is perceived. If the position or angle of light changes, whether the source is reflected or direct, the colors in the scene will change. The master photographer will recognize these changes to improve the work and subject matter.
Color in an image can help to generate a "feeling" in a photograph and an emotional response ranging from fear, to love, to anger or happiness. An image that has a blue cast is representative of a sad, gloomy, or somber mood, while red is perceived as causing an angry, antagonized, or irritable mood.
<a href="http://fineartamerica.com/art/photographs/green/all" style="font: 10pt arial; text-decoration: underline;">green photos</a>