A gray background is a good suggestion, I may try that.
As for the shadows, you need more lights. My "light tent" is a cardboard box with holes cut in the sides and white muslim stretched tight and glued to the outside. My cousin's husband is a professional photographer. This was his suggestion.
I have 1 overhead light with a 100 watt bulb and a halogen light on the side.
For the white balance, your camera may have a setting. The one on my point n shoot puts too much blue in, so I adjust white balance in post-processing with GIMP. My pictures got MUCH better after I started using close-up mode and a tripod.