Do a Google on any of the major paint companys, most have sample room that you can paint right on line to check what it would look like.
In Lowes or HD there's what looks like a TV set in the wall over by where the paint samples are that you can also pick the color you have on your counter top and see what colors they think would compliment that color.
Off the top of my head I'm thinking a gray tone.
When you do paint it make sure to wash down all the walls with about a cup of bleach in a gal. of warm water to get the soap scum and any mold spores off the walls or the paint may now stick.
Since bathrooms are subject to more scrubbing and moisture I like to use latex enamel paint on the walls, and no it's not oil based and no it does not have to be shiny like most people think when you mention enamel. It's just a far tougher paint.
Paint the ceiling flat white, you never want to use anything with a shine to it or evey flaw will show.
Buy paint that says kitchen and bath or just had a midicide to it. Home dept. sells it right in the paint dept. and will add it for you as there shaking the paint if you ask them to.
Try to pick a light color, a dark color in a small room like that will feel like a cave.