I hope everybody uses a calibrated and profiled monitor, otherwise everybody sees different colors. For those interested in getting serious, I can recommend Fraser Murphy & Bunting "Real World"-series "Color Management" book. Good, faithful color reproduction is quite tricky, and often disappointing, as often enough the non-standard color is what our brain/psyche likes! Particularly oversaturated colors are psychologically desirable eye-candy. That's the reason why the more saturated films such as the EktachromeVS series sold better then the neutral AgfaChrome. In Digi-age, the default setting in picture styles is one with increased saturation, whereas neutral is hidden deep in the menus.
One way to standardize color is to photograph right before/after or even with the subject a neutral grey card board, or a so-called
color checker (MacBeth). There are the old wet chemistry boards, and
newer digital color checkers as well as some
kits. Then you can check on the monitor using the eye-dropper, whether the monitor/file RGB color values are the same as the ones indicated with each of the color squares, and then do color adjustments to bring the two as close as possible. Grey card boards are about $10, color checkers are about $30-50 (as far as I recall).
An other thing ronalshanko alluded to, is to play with the white balance of the camera. Some cameras permit to select a color temperature in the 2500 - 10000 Kelvin range, or so. But how to know what to set it to? Here comes the infamous color meter, best known is the Minolta version, I own the
ColorMeter III, costs around a grand, so only for the truly dedicated. Remembering that low color temperatures result in yellow-red colors (think old light bulb), standard daylight is around 5000-6000K, and higher temperatures result in blue casts (overcast sky, shadows). Then you can do an educated guess of how to set the white balance.
If the color temperature is outside that range, then you have to deal with color correction filters, the Wratten 80 and 85 series, and use the
Mired chart to obtain the right filtration for source light and film/sensor setting.
With the water lily shot, the overcast sky resulting in high color temperature will emphasize the blues, as evident in the image, and as a result also emphasize the magenta of the petals. Hence, the result is not entirely surprising.
Last but not least, the surroundings play a major role. When light is reflected off a colored surface, the reflected light will increase that color. It can affect color temperature in the ideal case, but may also introduce color casts that are unrelated to color temperature, and are much harder to deal with. Additionally, those color effects may be directional, which is a real pain to correct: think adjustment layers with gradient masks, yikes.
Linear Mode
