Digital technology gives photographers a level of control over colour that the average film photographer could only dream about. Using Photoshop, it's possible to remove colour casts and adjust overall colour as well as working on specific tones and hues.
With so much control it can seem rather daunting at first, but provided you always work using Adjustment Layers or Duplicate Layers, you can revert back to your original image and start again whenever you like.
The aim of colour adjustment and white balance correction is often to produce a neutral image. While this may be what is required on many occasions, it can also strip the atmosphere from a scene.
Colour is one of the best ways of conveying mood or atmosphere in an image, so rather than worrying about getting colours technically 'correct' or neutral, it's often more important to think about the emotion or sensation that you want to convey.
For example, give a misty image a hint of blue and you'll shiver inside every time you look at it, but give it a touch of yellow and red and suddenly it seems that the sun is starting to burn off the mist with the promise of a warm, sunny day.
A rich, warm autumnal image is very often far more attractive than a technically correct version. The decision is yours, but the most important consideration is the image itself and what works best.
Curves offer you control over image colour by manipulating the RGB channels separately.
Although the Curves control is most commonly thought of as a way of adjusting brightness and contrast, it also provides a great method of adjusting image colour, because you can work on the individual colour channels of red, green and blue.
It also allows you to manipulate the colour in the shadows, midtones and highlights separately.
When the Curves Dialog Box is opened - using Ctrl+M or Image>Adjustments>Curves (or by creating a Curves Adjustment Layer) - the channel is set to RGB by default, so use the drop-down list to select the channel you want to work on. Just click on the curve and push it up to increase the channel colour's input, or down to reduce it.
When you adjust the level of red, green or blue in an image you are also manipulating their opposite colours - which are cyan, magenta and yellow respectively - so reducing the amount of red in an image, for example, increases the level of cyan.
The colours in raw files taken directly from the camera often appear dull and flat and in need a boost.
In addition to tweaking the tones and contrast in your image, curves can also be used to correct colour.
Experiment with the individual red, green and blue for cool creative effects.
Useful Tip: The Select Color Range Option
A useful tool for making a quick selection, or refining an existing one, is the Select Color Range option. Choose the Sampled Colors option, then use the Eyedropper tool to target an area.
Use the Fuzziness slider to determine the range of colours included in the selection. To add colours to the selection, click on the image - or the preview - with the +Eyedropper and remove them with the -Eyedropper.
Color Balance Adjustment Layers
Using an Adjustment Layer to alter colour balance means you can re-edit the results at any time.
The great thing about Adjustment Layers (Layers>New Adjustment Layer) is that they allow you to make changes to images that you can then adjust or undo whenever you like.