Here is your photo with a few simple adjustments. I assumed that your background was neutral (grey or white) and used it to adjust the color of the entire image (technically for those keeping track, I hit it with the grey eyedropper in the levels panel) and then brought the levels into range (i.e. I brightened it up) then ran a bit of sharpening (unsharp mask, Amount 150, radius 0.3, but this will depend on your image resolution, and this one is rather low resolution)
So in the end, this could be done with, as the others have said, a color balance adjustment. Assuming you're using a digital camera, it should have a setting for the type of lights you're using, and if you're not sure what it is, try a shot with each color balance setting and see which one looks best. After that adjust your exposure to brighten up the image. There is usually an exposure compensation setting (dig the instructions out of the trash), find it and set it to somewhere around +0.5 to +1.5 and see if that helps things (and the tripod is a great suggestion, since the exposure compensation is probably going to slow down the shutter speed.
It's possible that your camera can do a bit of the sharpening for you too. While you've got the instructions, see if there is a sharpness setting and if so, turn it up a notch or 2. If not, then look at what you're using to crop your images and see if it has any sharpening function. Play with it and see if it brings out the details a bit better...