Minolta DiMAGE Viewer - Manual (Page 35)

In photography, red, green, and blue are the
primary colors. The secondary colors, cyan,
magenta, and yellow, are made from combin-
ing the primary colors: cyan = blue + green,
magenta = blue + red, and yellow = red +
green. The primary and secondary colors are
grouped in complementary pairs: red and
cyan, green and magenta, and blue and yel-
low.
Knowing the complementary colors is very
important in color balancing. If the image has
a specific color cast, either subtracting the
color or adding its complementary color will create a natural looking image. For example, if the image
is too red, decrease the amount of red; if the image is too yellow, increase the amount of blue.
Adding or subtracting equal parts of red, green, and blue will have no affect on the color balance.
However, it can change the overall image brightness and contrast. Usually, no more than two color
channels are needed to color balance an image.
Color balancing is a skill that develops with practice. While the human eye is extremely sensitive in
making comparative judgements, it is a poor tool when making absolute measurements of color.
Initially, it can be very difficult to distinguish between blue and cyan, and red and magenta. However,
adjusting the wrong color channel never improves an image; subtracting blue from an image that is
too cyan will give a green cast to the image.
35
AN INTRODUCTION TO COLOR
RED
GREEN BLUE
CYAN
MAGENTA YELLOW