Here's a tech question. With the D600/610, I used to have Auto WB (raw) with the SB700 mounted on top or off camera. The resulting white balance used to be excellent with not much need to change. With the D750, I see that Auto WB produces a much warmer image with SB700. Changing the WB to 'Day light' in post sorts out the issue with a slight hint of magenta which again can be fixed easily.
There is a flash WB option also, but I found it unreliable on the D750.
Just wondering what others are using as WB when used with a Speedlight.