All you have to do is make sure that you match the camera's white balance to the current lighting conditions.
- Presets. Even if you use your flash to shine some daylight onto the scene, onboard flashes usually don't have enough punch to provide full coverage, so some of your image is going to be off-color. If you choose the white balance preset that matches the lighting conditions, the colors will better match the true colors of the scene. Just don't forget to change the white balance setting when lighting conditions change.
- Manual white balance. You may not want to carry a white (or gray) sheet of paper around with you wherever you go, but this is one of the best ways to make sure that your photos' whites are clean and bright. If your camera has a manual white balance setting, just fill the frame with the sheet of paper and register the white balance.
- Shoot in the raw. Shooting RAW format is an excellent option for getting the right white balance. The file is unprocessed, so you can use software such as Adobe Photoshop CS2's Camera Raw to apply the appropriate white balance.
- Quick fixes. There are many different ways to adjust color in image-editing software. While most automatic adjustments are quick, they're generally inaccurate. But if you don't want to fuss too much, you can try several quick fixes. If you're using Adobe Photoshop CS2, for example, look at the options that Photoshop presents in Variations (Image > Adjustments > Variations). You can also use one of Photoshop's Cooling Photo Filters to make a warm (yellow) image cooler (bluer) or warm up a blue image with one of the Warming filters (Image > Adjustments > Photo Filters).