The Hue and Brightness settings are not available within the NVIDIA Purevideo Decoder Properties Color panel if the de-interlacing mode in the Video panel is set to VMR7 (Video Mixing Renderer) as shown in the image below:
Additonally, if the video player you are using for DVD or HDTV playback has its own properties with a setting for rendering format, if VMR7 is selected, you will not be able to adjust the Hue and Brightness settings. Under Microsoft Windows Media Ceneter 2005, the default mode set by Windows is VMR9 which supports Hue and Brightness. With Overlay or VMR9 setting, all color controls are available. This is a Microsoft limitation of the VMR7 mode.