We used to tell the Realtor to prepare the home buy turning on all the lights, it would make it look warm and inviting as well as limit the use of flash and the harsh shadows that go with it. This actually did make the home look warm because incandescent light runs to the red.
But do we still need to do this/ The answer is YES and NO.
Below are two shots of the same scene, with and without lights on. Using our own formula for merging images we get a great scene without the additional lights and may prefer it at times over warming a scene.