You need to change the settings on your TV. Make sure that there is no energy saving or eco mode on and also make sure that the gamma is set to 2.2.
ChatGPT can give you instructions on this if you provide your brand and model of TV. Make sure to log into it for better repsonses.
What to do about my sister and my daughter
Unused rooms, heat storage and heat transfer


Actually several family members have tried to do this, and I have had my eyes tested.