"Black Galaxy" granite counterop

I have two questions:

1/  I will have "Black Galaxy" granite countertop installed soon.  I just wonder if the stains visibly shown on the black top.  Is it true that dark color of granite will show less stains?  I know the water stain will be gone by itself.    Does it need to seal it and what do you recommend?  Can I use the "granite care kit" sold on line for my countertop.  They sell sealers, stain cleaners, etc..

2/  Also, I will have "Black Galaxy" tiles in my foyer?  Does it need to be sealed just like my countertop?  Can I use the "granite care kit"  as I mentioned above?

Thanks in advance for your information,

JoAnna