You may be surprised to find that hue and saturation--not brightness--are the key to fixing your image's color problems.
The hue of an image is the actual color in question—Is it red, yellow,
blue or a combination thereof?
"Saturation" sounds like what you do to
yourself with a bag of Cheetos and an X-Files marathon on cable but, in
Photoshop or a similar application, saturation can be described as the
"pureness" of a color, where a highly saturated image looks full of color and a
less-saturated image appears washed out. Saturation works together with Hue and
Brightness to form the HSB color model.
The hue of an image is the actual color
in question—is it red, yellow, blue or a combination thereof? Saturation is the
purity of that color, along what might be described as a
"dull-to-normal-to-vivid" spectrum. Brightness is the intensity of the
color—this is the one you've probably fiddled with the most. But brightness
doesn't always solve an image's problem the way that hue and saturation
can.
In your software, changing the hue
changes the actual color in your image. That's not something you'll generally do
except to make either subtle changes, such as to compensate for a sickly skin
tone—or bold changes, such as to completely stylize the image with unnatural
colors. (Think Warhol.) If you've got people coming up a little yellow or
greenish, you can tap the Hue slider a bit in your software (in Photoshop it's
Image > Adjust Hue/Saturation) to make subtle changes. If you need to change
them from skin tone to a fairly deep green, you can do that, too. Just
slide away.
Altering the saturation of an image can
have wonderful results for the overall effect of that image. The key is that
increasing saturation can cause the rich colors in an image to become more vivid
while the more tame colors—tans, whites, light skin tones—will stay a little
closer to the original. The results: ruby red lips or vivid striped clothes or a
deep blue car body with richly tinted windows. Likewise, decreasing saturation
can be handy for making an image appear closer to black and white, or look like
it was taken on a rainy day, or for a "colorized" effect where part of the image
seem black-and-white and other parts seem to have just a little color, like an
aging color photo.
Too much saturation can look
fake—usually 5-20% will boost a photo nicely if that photo didn't start too
washed out. Even more saturation than that can sometimes rescue a poorly shot
image (or an image from a digital camera or scanner with bad color reproduction)
and give it a little visual zing.
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