Color definitely can make a difference. I've done some research, but am certainly NOT any kind of expert in this area! The basics off the top of my head are:
- Red provides energy, but too much really causes stress and conflict (i.e., "seeing red"),
- Green is relaxing, but too much will put you to sleep (which is why so many senior homes are this color),
- Yellow is good for concentration and creativity, but too much will make you hungry (which is why so many fast food places have yellow in their restaurants)
- Blue is also calming (there's actually a color called "Cardiac Blue" that's used in ICU's), but too much is depressing (i.e., "feeling blue" or "singing the blues")
White will make a room look bigger, grey is less fatiguing for the eyes (which is why the underside of the bill on most ball caps is colored grey) and black will make a room look very small.
I would suggest painting the room white or off-white then adding color with wall coverings, rugs, gobos, dividers or edge work. With all those options, except edge work, you can change things up as you get used to the room (or if you need to set a certain mood - it might be hard to play Cure songs in a bright and cheerful room or Burl Ives songs in a dark and gloomy area!).