The best colors for small bathrooms are pale pink, white, pale gray and yellow, according to SFGate.com. Each of these colors lends itself to producing the illusion of space, which makes them the ideal colors to use in a small bathroom.
Pale pink brings together both warm and cool color undertones, which makes it a good choice for confined spaces. It provides the intimacy of the warmer color tones with the spaciousness of the cooler color tones and lends itself well to small bathrooms.
Grays used in smaller areas encourage feelings of spaciousness. They can visually open up smaller spaces by tricking the eye into seeing reflected and shifting rays of sunlight.
Yellow resembles the brightness of sunshine, and a pale shade of yellow can create the illusion of warmth and spaciousness within a small area. Darker yellows can have the opposite effect; avoid these when choosing colors for confined spaces.
Light blues such as aqua and sea green can also create the illusion of space in a small bathroom. Even though they typically are cooler colors, light shades of blues and greens bring a certain serenity and calmness to small rooms, which can in turn make the room feel much larger than it actually is.
Warmer colors are not recommended for smaller spaces as they tend to make areas seem more confined. Dark reds, greens and blues are often bad choices for smaller spaces.