In photography, the light source plays an important part in the color of the photograph, because light emitted by various light sources has different colors. Photographers use color temperature to describe the dissimilarities in the color of light. The Kelvin scale is used to calculate the color temperatures of light sources. The lower the figure on the scale, the more orange or red the light is. Light on the higher end of the scale has a blue color to it. The color of the light in your scene also aids contribute to the overall mood of your picture. The more the light in a scene goes to blue, the colder the scene will feel, and the more red or orange there is, the warmer the scene will feel. For instance, candlelight, which gives an image a warm orange hue, has an approximate color temperature of 1800K whereas shade is usually about 7500K and gives your image a colder blue hue.
The color of light and the white balance setting on the A700 are linked in a very important way. To achieve correct color in your photos, the white balance setting tells the camera’s sensor what the color of the light in the scene is. If the temperature of the light and the white balance are matched, the colors in your photograph will look natural.
Have a look at other articles describing the influence of lighting conditions on photography:
The Diffusion of Light, Light types, The Intensity of Light, Light Direction,