[Stereodude]

Sorry - I'm afraid my experience doesn't tally with that. My Sony HDTV and my Panasonic HDTV both default to 16-235 RGB levelspace.

My two Samsung TVs my Hitachi TV don't. In the Samsung menu the proper setting for RGB 0-255 is labeled "normal" the setting for RGB 16-235 is "low". The Hitachi TV doesn't have a menu option to deal with RGB 16-235.

This is the expected behaviour for HDMI as per the HDMI 1.3 spec : http://www.microprocessor.org/HDMISpecification13a.pdf

Section 6.6 of this is :
"6.6 Video Quantization Ranges
Black and white levels for video components shall be either “Full Range” or “Limited Range.” YCBCR components shall always be Limited Range while RGB components may be either Full Range or Limited Range. While using RGB, Limited Range shall be used for all video formats defined in CEA-861-D, with the exception of VGA (640x480) format, which requires Full Range."

CEA-861-D defines the standard TV and HDTV HDMI specs used for TV (480i/p, 576i/p, 720p, 1080i/p, and now 2160p at standard HDTV rates) so the HDMI spec states that 16-235 RGB Limited values should be used for TV resolutions. Full 0-255 levels should be the default for non-TV resolutions and the not-quite-TV 640x480p square pixel 4:3 res.

TV black levels, whether in SD or HD or 4K, and whether YCrCb or RGB are 16-235 (or 10 bit equivalents) HDMI follows broadcast specs for broadcast resolutions. It follows the PC/DVI RGB specs for PC resolutions. Whether all consumer gear follows the HDMI spec is another matter of course. YMMV.

That's all well and good, but you get better image quality converting YCrCb video to RGB 0-255 or leaving it alone and sending it out as YCrCb. Your talking about theory and specs. I'm talking about practical application. One of the supported options shown in that spec has inferior image quality for playback of YCbCr video (which is effectively all video) vs. the other two. It just happens to be that's the one the Chromebox w/ OpenELEC defaults to (RGB 16-235). Since the Chromebox w/ OpenELEC doesn't do YCrCb over HDMI like CE devices such as DVD & Blu-Ray players do it should output RGB 0-255 since it has better image quality than RGB 16-235 and is allowable per the HDMI specifications.

By the way, Windows (7 & 8.1 at least) output RGB 0-255 from a Haswell iGPU over HDMI. You can control the output levels (for video playback only) in the control panel but the desktop and all other GUI elements are RGB 0-255.