Yet another way to mess around with the color in your image. From the menu, choose Image Adjust Color Balance. This tool is good if you want to be able to manipulate the bright colors, middle colors, and dark colors separately. This tool is also a bit confusing, so you'll want to pay attention to this. Towards the bottom of the window, you'll see that you can choose to work on either Shadows, Midtones, or Highlights. This selects what colors of the image you want to work with: the dark colors, middle colors, or bright colors.
The slider bars allow you to adjust the colors' balance. The colors at opposite ends of each slider are "opposite" colors - they are on opposite ends of the color wheel. The idea is that you can decrease the amount of a color by increasing its opposite color. So, for example, the highlights of your image contain too much red, you'd want to select "Highlights" and move the top slider towards Cyan.
Cool Links: Microsoft