There is simple syrup and then there is invert sugar. They are similar in that they are both sugar dissolved in water but they are not the same. As far as the initial cloudiness that is what happens before the sugar goes fully into solution in the water, the same thing happens with salt in water. For the record I'm not stating one needs invert sugar for back sweetening wine but that is what the OP posted.
It does take on color but perhaps, and just saying perhaps, at the dilution rate that one would use it in a white to back sweeten it may not change the color perceptibly.
@Vlabruz maybe if you have say a bottle of dry white wine you could try a bench trial with what you made and see how much color it lends at the sweeteness you're looking for before using it on your SP.
