You are going to have to leave your comfort zone on this one. Walnut is "brown", you have "pink" as a counter top. I would suggest going with another version of the colours already in the room. you have gray/beige and white. I would hesitate going white...but it can be done. You can move into the grays and be very happy (it would look very modern) or you can move into a beige that holds a hint of pink in it (not pink...but a blush of warmth). Or you could go really wonky and add in something like a brushed stainless steel look to the cabinets and have it go "space age". There are specs of blue/gray in this counter top. The next think to look at is an "ashwood" or dark gray wood presentation that has some blue in it. It would lighten the space yet still add drama that dark cabinetry offers.

I agree with divadeva. More lights. If you can add pot lights do it. If they're already there add task lighting and up the wattage on the bulbs on the pot lights (replace with LED and you can make them brighter because the wattage on LED is lower for brighter light). If you have all of that add decorative lighting. If ventilation is an issue find a way to move the air around or add air filtration. Maybe the HVAC is deficient. Maybe you can add a HEPA filter instead of the standard one that comes with the unit. Call an HVAC specialist to see if there is a way to boost air flow in the room.

Take photos of your cabinets and space with you when you shop for granite. Another Idea is to visit Home Depot or Lowes and buy some Single 12x12 granite tiles as samples just to get an idea of what might work. They have lots of choices. Not exactly what you want but close enough to help you zero in. The tiles can then be returned.

I did a house with nine bathrooms and it was so much fun. For the master bed we had his and hers separate ensuite bathrooms, so hers was feminine and victoruan; it even had a chandelier! His was white with a red shower wall and a blue and white border tile. The counter was tiled with red. It was a very cheerful little bathroom. The daughter's batH was blue and white, the border tiles and washbasin were Chinese themed. A very pretty bathroom. The two guest bathrooms were yellow and cream with hand painted sunflower accent tiles. One powder room was yellow and white, the other was beige with orange and green accents. It had a very whimsical washbasin with a hand painted frog inside. The pool house also has two bathrooms, more basic, mostly cream with wood accents. The colour comes from the stack of towels, red, blue, orange, lime green and yellow.