I have a D70S and up until this point I have been taking shots in Color Mode IIIa. The default setting is Ia. A photography website that I frequent suggested using IIIa (mostly for landscape/nature etc. photography). I like the color so much better than in Ia mode. The images are much more natural and warm.
I haven't had very much opportunity to snap portraits in IIIa-so far they look fine. What is ideal for people subjects?

 

I also use IIIa on my D70, but I go even further and set the saturation to "+ Enhanced", as well. Like Ken Rockwell says, "I'd use ++ or +++ if my D70 had it". I also adjust the White Balance to AUTO -3 to help with the "green cast" problem and to warm up the colors even more.

I rarely shoot people, but when I do, I usually just switch to "Portrait Mode" with the mode dial (the little symbol of a lady in a hat). This turns off all the above custom settings and chooses settings that are good for portraits.

 

I get on Ken Rockwell a lot for his easy to understand explanations of concepts and techniques with the Nikon and photography in general. I've tried his "+" settings but found them to be too much color for the kind of photography that I have the opportunity to do right now. But then again, I'll have tot ry and just switch it to one of the automatic settings for stuff like portraits.

 

IIRC, I'm set to mode IIa but 99.9% of my shots are RAW (NEF) with post-processing so the color mode (and White Bal) doesn't matter so much. If I was shooting for out-of-camera JPEG's I'd have to try some of these type of settings (mode, saturation, sharpness, white balance).

 

Srgb Mode 1 = people and natural look
Srgb made III = landscape or vibrant