[Hufvudet]

if you're using xrandr to set full range (0-255) output, then your TV needs to be set to match (so, color space 0). If you're a limited range on your TV, then you wouldn't need to use xrandr and you should leave the Kodi setting at default (non-limited range)

When using xrandr to set full range output, the TV needs to be set to match the Kodi setting. If Kodi is set to limited range, then the TV needs to be set to limited range too (although some TVs like Panasonic plasmas ignore the infoframes and always expect a limited range signal).

Everything at default (the same as setting limited range with xrandr and full range in Kodi) provides properly tagged limited range signal, but the levels are scaled twice (first by Kodi limited->full range, then by GPU full->limited range), causing banding and clipping BtB and WtW. (PC monitors will get a full range signal, but that is still scaled once and has the same problems.)

Sorry to disturb you..so the correct settings for:

Chromebox with oe 15/16 xrandr to full
Panasonic Vt60 set to limited (option are Auto, Full, Limited)
Kodi set to limited

Right ? Thank you

Right! I have st60 and have researched this thoroughly.