This is heavily dependent on the lenses used ,your approach to WB ,the raw conversion software and your efforts to profile your camera . Thats just to get a converted file ..then you factor in any presets used to establish your personal aesthetic .
Prior to the newer G Nano coated lenses ..most Nikkors produce a warm (yellowish bias from the coating ) . I have had a devil of a time getting the yellow out with the 135DC for example . The G Nano coated lenses render neutral .
My approach to WB (when I am being careful ) is to use an Expo Disc …this typically results in a cooler WB than Nikons AWB . This is a matter of taste as many Pro s used a fixed Cloudy WB (6500) .
The conversion software makes a big difference in “straight out of the camera “ color with the D4 sensor . Capture NX2 ( not a user friendly software ) produces very nice neutral color …..LR5 ….can produce the “acid” Jono speaks too unless you tune it out . Look forward to hearing from the Capture One users as they take up the new Df .
Finally the Camera calibration using a Passport Color Checker works well to further standardize and neutral set color in LR .
Carry this further and use a Film Emulation preset and I think you can obtain an aesthetic free of any bias (other than what you intend ).
Having used essentially all of the Nikon sensors over the past 3-4 years …I totally agree that they have a yellow -green bias . I shoot baseball,polo and surfing in the winter and grass can be difficult as well as keeping the water blue enough . Last year I calibrated my D800E bodies and cleaned up my workflow …was pretty happy with the color . We will see with the Df ?
The D600 (with the Sony 24MP sensor ) is pretty great right out of the box in Aperture (which my wife uses) . I ve been surprised at the lack of take up in the D600/D610 as the prices have fallen to just above $1500 .