Make sure you have the white balance set.
http://support.nikontech.com/app/an...l/a_id/15996B White Balance
The color of light reflected from an object varies with the color of the light source. The human brain is able to adapt to changes in the color of the light source, with the result that white objects appear white whether seen in the shade, direct sunlight, or under incandescent lighting. Digital cameras can mimic this adjustment by processing images according to the color of the light source. This is known as "white balance." For natural coloration, choose a white balance setting that matches the light source before shooting. Although the default setting, Auto, can be used under most types of lighting, you can apply the white balance setting suited to a particular light source to achieve more accurate results.
a Auto (default setting) White balance automatically adjusted to suit lighting conditions. Best choice in
most situations.
b Preset manual
Neutral-colored object used as reference to set white balance under unusual lighting conditions. See, "Preset Manual" (A 66) for more information.
c Daylight White balance adjusted for direct sunlight.
d Incandescent Use under incandescent lighting.
e Fluorescent Use under most types of fluorescent lighting.
f Cloudy Use when taking pictures under overcast skies.
g Flash Use with the flash mode.
The effects of the selected option can be previewed in the monitor. At settings other than Auto, the icon for the current setting is displayed in the monitor (A 6).