According to How Stuff Works, pink, blue or green are ideal for a workout room. Pinks and blues lend a tranquil quality, so they work well for yoga rooms or other rooms designed for less intense workouts. Green, on the other hand, helps decrease distraction and increase concentration levels.
Most workout rooms have a lot of equipment or bulky exercise machines. These rooms should have lightly colored walls. Dark colors make a room feel closed-in or small, especially in combination with a busy room. Brighter colors, such as white, off-white, or pale shades of pink, blue or green, make a workout room feel larger and more welcoming.