Parents' Bed & Bath

For the parents' bedroom, use KM4186-1 "Bohemian" on the walls. If that feels too neutral and you want a bit more color on the walls, try KM4162-1 "Natalia" (also nice, if a bit lavender-y).
The silvery nature of Bohemian will give the bedroom a calm feel, and will look beautiful against the dark woods of the furniture and floor. It will even pick up some of the color of the bathroom countertop limestone (LT/OTM/776 - Seagrass Honed) when seen through the doorway.
Creamy neutral and beige linens (KM3993-1 "Cloud of Cream" and KM3948-2 "Meadow Brook") will work best (1&2 on photo above). Accents, such as throw pillows, artwork and window treatments can be in darker mauves, brown, and even red would add a bit of liveliness (KM4163-1 "Mauve Star", KM3767-3 "Plum Island", KM4192-5 "Raw Earth", and AC217-R "Terra Rosa"). These are 3, 4, 5 and 6 in the photo above.
In the bath, use KM3537-1 "Iced Chai" on the walls. This will be crisp and clean against the soft colors in the natural stones and tile. Countertops and soaking tub surround: LT/OTM/776 "Seagrass Honed". Floor of sink/toilet area and shower walls: TT/OTM/02 "Ivory Polished" with Laticrete grout color #3. Shower floor: SA/OTM/CST2 "Chestnut 2" with Laticrete grout color #3.