Brightness, contrast, colour etc.
It’s in the lounge, fairly well lit room by day
Anyone wear glasses in the house?
Do they use them to watch tv or do they go without?
Factor that in. Just go default settings then play with the brightness to begin with on somthing you normally watch.
Of course, the built in presets should satisfy.
Sorry couldnt find a manual online... but if you have one, it should be pretty straight forward to learn navigation of the 'picture' menu.
Default settings on most TV's these days includes enabling many post processing features. Even the new Sony OLED looks terrible out of the box until you disable motion flow.
settings will varying according to your environment, usage, personal preferences etc.
try to control the lighting.
start with the cinema or movie preset.
turn off all the auto stuff.
adjust to your liking.
or pay someone to do a professional calibration.