A modern style bathroom design pictures is fresh and crisp with lots of clean lines. Usually your design will work best when you incorporate minimalist elements. If any rule is followed, this is probably the most important one. There is no real restriction on the colors that you can use for your bathroom design, but often the basic color palette is done in neutrals like whites, grays, and blacks, accompanied by dark woods, all of which is best accented with a brighter color like a red, blue or green.