The image on top is the actual image I shot early this morning on a louvered blind in our dim shadowy den. The bottom image is after 5 minutes editing in Adobe Lightroom II.
I didn't add color, texture, or elements that weren't already in the image (except for the vignette around the edge); I simply tweaked the white balance and boosted some color and contrast.
It's a great program that a lot of serious photographers are using; as such it's a bit expensive ($299 from Adobe, $239 @ Amazon). Or around $100 if you qualify for an educational discount.
The Adobe website does have a free complete trial version you can use for 30 days with no strings attached. (Don't do the free trial unless you have the cabbage to pony up when it expires, or you'll hate yourself.)
Or if "you're a PC" I've used a great FREE image editor called Photoscape.