Are you actually located in India as is indicated when I "clicked" on your name. Styles may be different from US.

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.

Granite is more suitable for Kitchen countertops .

Hi,  Go for Jet black granite for counter top. It would look classy with your white ceramic wash basin and beige wall tiles. And go for above counter wash basin.