When shooting raw, the data is what the data is. By changing the picture controls, you change the way it is being processed before it gets displayed (or saved to a new file). What the histogram will display is the result after the processing by the software. The amount of space shown by the histogram is the amount of room you have left for the rest of your post processing, in gross broad-sweeping terms.

If you tend to use the "expose to the right" system, and you prefer to process your pictures similarly to the picture controls, you might be better off setting those controls in the camera. That way the JPG shown on the LCD will approximate the raw results after post processing, thus letting you see if your exposure settings will present a problem later.

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Joseph K
Seattle, WA, USA

D700, D200, D70S, 24-70mm f/2.8, VR 70-200mm f/2.8 II,
50mm f/1.4 D, 70-300mm f/4.5-5.6 VR, 18-70mm f/3.5-4.5 DX