A soft, warm grey shade would look lovely, and can be as dark or light as you want. A warmer shade will work with the brown stained wood floor, and the grey will complement the black granite. You could have an undertone of green, blue or tan if you didn't want a pure grey. And it would look nice with any silver metal hardware, either polished or satin/brushed, so you could choose pewter, chrome or nickel. It would still work with white trim too.

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.

Is it burgundy granite? I think we need to see it. I like gray with burgundy.

Hello Abinash, Correct me if I am wrong in my guess that you liked the basin so much that this entire unit was build around it :) that too in the centre of the room. Jokes apart, the base cabinet doesn't provide a few inches gaps to the user for keeping the foot comfortably while using a hand wash. Have you considered the water proofing and maintenance of this unit as what it appears it is wood with laminated top as of now. Do you have a floor plan, as it is a surprising positioning of a hand wash. Thanks, Nitin CORNERSTONE DESIGNS Bangalore