COLOR CORRECTIONS IN THE DARKROOM

EVALUATE THE PRINT’S COLOR

Once you have printed a full-size trial photograph at the correct density, evaluate the print’s color. Assess the print under the same type of light source in which you will ultimately present it. If the presentation venue is not known, use daylight. Look for color casts that you can identify as red, green, blue, cyan, magenta and/or yellow. For example, the cast may be greenish, which indicates the presence of too much green. Or the cast may be purplish, which would indicate the presence of excess magenta and blue. Usually areas of the print that should be neutral gray are easiest to evaluate.

Instead of trying to identify a cast from six possible colors, you can halve the possibilities by determining whether the cast is warm or cool. On our color wheel, the warm colors are at the right of the vertical axis (magenta, red and yellow) and the cool colors are at the left of the axis (green, cyan and blue).

http://www.reframingphotography.com/content/color-corrections-darkroom

Great site for reading up on colour darkroom techniques