Basically, you're talking about applying video filters to enhance the image. But first you may want to examine the conditions of your shoot. The most frequent cause for "weak color" is shooting with too little light. Cheaper, consumer grade video cameras are optimized for the sotrs of conditions your average, point-and-shoot consumer. That is generally in lower light conditions. However, your Canon XL2 is a prosumer camcorder. It is optimized for situations a semi-pro would encounter. So the camcorder "expects" proper lighting. Try adding light to your next shoot to see if that doesn't help.
So for the video you've already shot, you are looking for help in color correction and/or grading. Since I use Sony Vegas to edit, I have a link to a couple of articles on how to go about color correction. Even if you don't use Vegas, the concepts in the articles are applicable to any NLE. They discuss how to go about increasing saturation, contrast, brightness and even hue. Applying these lessons to your previously shoot footage will help. But really the best plan is to shoot under proper conditions.
Good luck with your future shoots.