If you don't want a ton of color, go with white/grey, and add in some yellow accents, as shown in your picture. If you want more color, how about a nice, mild yellow? Good luck!

While I like grey with yellow, dark colors on bathroom walls steal what little light there is, often resulting in the inability to even see your reflection in the mirror. Try wainscot with the saturated color below and white or very light grey above.