I agree with the advice above. Get a friend who is good with color to help you pick the best white, Theres many of them and they can be tricky you want the color to work with both the counter and cabinets. Replace the large mirror with two smaller framed mirrors or one large mirror with a frame. The accessories on the wall could be removed or updated. Change the floor mats to new fresh white.

The window treatment over the tub should be changed to match the other window, or if budget permits use shutters on both windows. They are great for privacy and light control. Be sure to use a composite as the material is stable in rooms with moisture, then if you want to add some softness, a faux roman valance would look lovely and current.

I know you requested some color, you could pull that in either as an accent color on the shower curtain, an accessory on the counter but not the towels, crisp white would work best here. Pick one color and use variations of it.

What a lovely thing to do for your wife.

Good luck!