I think it is very much personalised. I have 2 lime green walls in my office at home and I know lime green isn't to everyone's liking. If I were to sell the place I would paint them back to their original colour.
Some people when looking at a property can't look past the furnishings or paint on the walls and are immediately turned off by it. So if I were renovating a property with the intent to sell (or rent) I would keep everything as neutral as possible and leave it to the new buyers to add their own touch to it.
If I were to do the accent wall then it would be a darker neutral shade of what's on the walls but that can have things looking a bit bland.
I would say the 'feature wall' is less common these days - they were big 10yrs ago.
If it is something for sale or for an IP I would keep it neutral but not too bland.
If you want to give some variation then perhaps do 1-2 walls in the house in a different strength to your main colour. For example if your main colour is 50% Hogsbristle then do the headboard wall of the master bedroom and the tv wall of the living room in 100% Hogsbristle