The first issue is that you're probably not viewing on a calibrated monitor - so no matter what you're capturing, you don't really know what you're looking at! Next, be aware that the LCD on the camera is also NOT calibrated, and most of the D2x that I've seen (note: not D2xs) have a distinct cyan tint to them. That includes mine. It is usually a surprise if the LCD looks the same as on a computer screen, at least as far as color goes.
The next consideration is what your white balance is set to. You're shooting JPEG, so the color balance - the digital equivalent to choosing between daylight or tungsten film - is baked into the output file. Usually folks leave this set to auto white balance, but I didn't find AWB all that accurate until the generation after the D2x. Moreover, even on the D2x (and D2h), that white spot on the top of the pentaprism is the white balance sensor. If you're wearing a billed or brimmed hat, the hat can interfere with the white balance sensor. Ask me how I know this...
I have the same older 50/f1.4 and it does not produce particularly blue coloration on my D2x, viewed on a calibrated monitor and with reasonably well controlled color management.
You could try setting the white balance a bit warmer (+1 or +2 on whatever is set now), but I'd only do that after getting a handle on your monitor calibration. What you see as too blue may look normal to others, or potentially even too red!
It does not sound to me that you have a problematic camera. At worst it might have the previous owner's white balance bias set in it, and probably not even that.
_____ Brian... a bicoastal Nikonian and Team Member
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