Color-correcting or white-balancing images is a complex process, but with Lightroom it's a breeze. To white-balance an image, navigate to the Develop module and open the Basic panel to view the white balance controls sliders. Drag the sliders to change the overall color temperature. Even better, click the White Balance Selector tool (or press W) and position the mouse pointer over a color that should be neutral. (Try to avoid something that's pure white; in fact, light gray works best.) As you hover the mouse pointer over the image, a zoom view of the pixels with their RGB values is displayed below. In addition, the Navigator preview changes to display a preview of the white balance if the area is clicked. Click in the area that looks best.
If you're in a hurry, you can have Lightroom automatically correct the white balance of your image. Simply click As Shot and choose Auto from the list (see Figure 3), or press Shift-Command-U (PC: Shift-Ctrl-U). This option won't always provide the best results, but it's handy when you're in a hurry or need a white-balance starting point.