The paint color you should avoid in bathrooms is red. Additionally, you should avoid stark colors like yellow, orange, or black in bathrooms. Even bright whites like Chantilly Lace may be a big mistake when painting a bathroom. What works best in bathrooms are neutral colors like light grays, warmer off-whites, and calming, soft blue-greens.
Your current bathroom decor, furniture, and fixtures should inspire paint color ideas. That includes coordinating wall, trim, and ceiling paint colors with existing bathroom cabinets, tiles, sinks, and vanities.
In small bathrooms, use brighter shades like warmer off-whites, lighter greiges, and crisp white paint colors to open up the space. If your small space gets plenty of natural light, you can go a shade darker.