Barb Siddiqui

I've tried several different settings and am having trouble with a yellow-ness in all my photos.
I'm using a FujiFilm FinePixA500 digital camera on a tri-pod, and this photo was, as I understand it, done on 100 ISO, +1/3 Exposure Compensation, with added 'brightness' that comes up by itself and I can't seem to repeat from the menu. I used no flash, with two 100watt full-spectrum daylight bulbs in the fixtures, one placed outside of and in front of the tent, the right one filtered through the side wall. I don't have any 'bounce cards' or additional lighting at this time.
Any suggestions as to how to further whiten the background in the shot? All the tent and background in it is white.