I would recommend you do a neautral color choice depending on what your house and your style is like. Do you like warm tones = Beige or Taupe...Do you like cold tones = Greys or whites. I would not go based on a shower curtain. You can always change it once you get tired of it. Keep it neutral and you have have a bathroom that will have many faces as the years go by.....as far as the cabinet...depends on your color choices.....painting is definitely a way to go to change the way it looks along with the hardware. I would also go to your local fabricator that have remnants(leftover pieces) to change the counter and change the sink. Sinks are very inexpensive about $65+ if you can also change the shape of the sink to a rectangle for a more updated look. Currently we are finding that most clients tile the exterior floor and the shower only. You can also keep the mirror and add a frame or change it for a large medicine cabinet (recessed) and also add a frame to mimic a mirror while having storage......show us your progress...