By painting it you will ruin the granite. You cannot change the color of stone. How about lightening up the room another way - lighting, accessories, window treatments, throw rugs?
Painting it is not an option, so if you are keen on having a lighter countertop, you need to replace what you have.If your budget is light, granite is not your first go-to solution.
Laminates would be your entry level option and then tilling. However, I'd look for other ways to lighten and brighten - like a new backsplash, better lighting etc.
How about adding light and reflective countertop appliances and cutting boards? Treat the gorgeous black granite as the backdrop.
CONTACT PAPER the color you want.
You will need to buy a whole new countertop and replace the black one
Contact paper is not recommended for use as a counter-top covering.
Any tiny tear or peeling of seams will invite bacterium to harbour and grow.
It will be impossible to keep the countertop sanitized, which is necessary for any food preparation surface.