I was blown away by the picture he starts talking about at 11:40 - the three images below are all the same picture*, just with a different color palette loaded. He also has palettes for each scene at different times of day, for nine variations in all. This was done to reduce ROM requirements in a Plug & Play X-Man game.
Over a forest:
Over the clouds at night:
Over a city:
* note that my crop from the video wasn't consistent so the images are slightly offset from each other
Over a forest:
Over the clouds at night:
Over a city:
* note that my crop from the video wasn't consistent so the images are slightly offset from each other