It's a Panasonic plasma from 2012. Model is TX-P42X50B and has native display of 1024x768. It does have 1080p and 720p modes. I use 1080p/50Hz for CE.
It still gives a great picture - I won't upgrade it until it breaks
For the true color replace kernel module/driver from addons/libreelec settings/drivers. I have panasonic plasma too, and this fixing it.