One thing that I was pondering over this, is the setting of the Auto White Balance. On the D7000, it is a bit of menu push, but you might like to check just to be sure. In the top lcd, the WB might have a * alongside it indicating that you have purposefully, or inadvertently added some color shift to the white balance setting.
This happens to me occasionally, as I might change for say fluoro (always a bit green so I might top it up with some magenta,) or perhaps add some extra yellow to make my sunsets glow.
Menu>White Balance>Auto>Auto1Normal> gets you to the little color spread chart and you can see if you have something else other than A-B 0 G M 0 BTW, Auto>Auto1Normal> will depend on what you have white balance set to. I just use it as the example. All others by pressing the Right fourway dial will get you there.
Now, you probably know all this already, and if so I apologise. Just in the heat of great creativity, its possible to go one button press to many and then not remember how.
Love that D200
.. I set out to discover the inventions of God. -John Muir