I second the info already given; just get another RETF or even two, no more. White's get large quick and will most definitely eat them.
I do have a yellow headed day gecko, it's full grown, the size of an anole, that will be in the same tank. They aren't aggressive towards other species and are diurnal where as the RETFs are nocturnal.
I checked this with an experienced herper. I have already gotten tons of crap already at the thought of putting these two together, and I would not recommend any combinations as I don't have the experience to. I got my info from an expert, but in general you would not mix anything as 99% of things don't work.
Your best bet is adding RETFs as they are happiest in groups anyways.