White balance is used to adjust colors to match the color of the light source so that white objects appear white. Subjects may be lit by several different light sources, including sunlight, incandescent bulbs, and fluorescent lighting. The bulk of white balancing in photography consists of color temperature correction. You’re correcting for a cast produced by the color temperature of the light, which lies along the blue-yellow spectrum. While white balance presets aren’t the most accurate way to color correct, they’re an easy way to get started. Adding cool hues will give images a shady or night effect, while adding warm hues will give images a sunrise or sunset effect.