The white cast can happen when the emulgator foams a little bit and then the gum stabilizes the foam. So I would try to play around with the concentration of the emulgator and the gum to where the emulsion is stable and it doesn’t foam as much. The emulgator INCI does have two surfactants (Lauryl glucoside and Myristyl glucoside), which can be problematic, when the formulation contains a high concentration of gum to stabilize the foam. If it still foams after you lowered the emulgator I would try to use another one. You can also try to add a litttle bit of dimethicone, which helps to get rid of the white cast.