Oftentimes there isn't a lot of thought put into bathroom paint colors. It can be overlooked in a whole-house palette or undervalued because of size, but those are two reasons to give the bathroom some attention. It doesn't have to conform to an overall scheme, so you can have fun with the hue. And typically, the small size of a bathroom means the color has more impact. These questions will help determine a path to color bliss.
For a private space, such as a master bathroom, you can express your whimsical side knowing no one will judge you for your choice of bright salmon pink or a favorite team's jersey colors. Whatever makes you happy is fair game. For a public powder room, however, you'll want to consider your guests. No one wants to close the door in a small space and be assaulted by vivid walls. Also, a generous gesture for your guests is a hue that reflects well on skin tones such as blush pink, butter yellow, or rich ivory.
Does the room benefit from windows or skylights? Natural daylight affects color, so pin up paint chips and check them during the day and also at night when the lights are on to be sure you like the hue at both times. If the bathroom has no natural light, check that the hue benefits from the kind of lighting (incandescent, halogen, or LED) and fixtures (sconces, pendants, or overhead) that you have. Creamy white, golden tan, and dove gray are safe choices for nearly every kind of light. Greens and blues, however, change dramatically in different lights, so tape up a variety of chips before you pick.
What is the function of your bathroom? If you need to get children awake and moving in the morning, paint the bathroom a color that has some punch, such as the deeper shades on the inner edge of fan decks. You can also have fun with multiple hues. On the other hand, if your bathroom is a soothing oasis, where you go to pamper and restore, you don't want royal purple and lime green fighting for attention. Choose pale, nondominant paints that are on the tips of a fan deck. Watery blues and greens are particularly soothing shades.
Finally, consider how much color you'll actually need. You can get a lot of effect from a small amount on just the wainscoting, the vanity, or even the ceiling. In a small bath with limited space, you can use a more vibrant shade. In a large room, go for something tame on the walls and save the dramatic hues for towels or window treatments.