Adjusting the colors in your image is an area of photo editing that many find time consuming and very confusing. However, it need not be that way. Here is an explanation of the RGB color space, which you will most likely find yourself using.
The principles discussed here apply to all photo editing software if you are working with RGB (all the ones I know of can) so is applicable to Photoshop Elements, Photoshop, Painter or any of the other products out there.
Once you have grasped the basics explained here you will hopefully find color adjustments make a lot more sense and your results will improve accordingly.