Color balance is critical and can come out wrong due to all sorts of factors: incorrect camera settings and/or odd lighting conditions. The computer allows you to adjust the color balance after the shot is taken, which can save many an image.
If there is an area in the photo that has a neutral gray subject, it should be easy to correct the all-over color. If not, it can be surprisingly tricky.
However, your computer monitor really has to be calibrated to make color adjustments, or the images may look good — only to you.
Bottom Line: Adjusting color shifts in photos can make a big difference.