Light pastel colours are always nice (especially when you want the room to look larger). Stay away from pinks and reds and red-browns, and go towards blues, greens, yellows and purples that have a high blue content.
Relaxing colors I would assume are the less intense colors. The darker warm (red, yellow, orange etc) and almost any shade of blue/cool color is pretty relaxing.
I was thinking orange for the kitchen ;)