I notice that the viewfinder’s colour Gamut on my Z 7 doesn’t display the Ultra Violet range accurately. I saw this when I was snapping the screen saver on my iMac’s Retina Display.
I tried adjusting the viewfinder’s Brightness up and down from Zero, and put the Colour Balance a little closer to the UV end, but noticed only a slight colour change in the viewfinder. The colours of the Live View screen however, are much closer to the actual colour gamut of the iMac’s screen and final image.
On another point… During an outdoor shoot the other day, the hazy sun disk, shining through the thin clouds, couldn’t be seen in the viewfinder.
I imagine that the viewfinders on both the Z 7 and Z 6 are the same. I don’t know how they compare to other brands of Mirrorless cameras though. Seems to me that Nikon needs to improve the viewfinder’s accuracy, since this is the primary conduit between a photographer and the outside world. Maybe in the next Z.