[Milhouse]

I know in the Popcorn Hour C-200 settings you can specify which color space to generate, presumably this is to work around duff displays or amps that mangle/misinterpret the colours. Not aware though of such a setting in XBMC or the Pi (config.txt). In theory such a setting shouldn't be necessary, but thanks to outfits like Onkyo it is... :-(

I'd be very surprised though if Onkyo are still stuffing up the color space conversion, as your amp is much more recent than mine.