What he said. We also have a granite/quartz countertop. We were sensible and got white, mainly because our glass splashback is dark blue (surprise,) It has not needed to be resealed in 6 years and still looks new. We got the sink cut out made into a chopping board as well. Maybe that is an option as the granite places can create an off cut into a reasonable cutting board for a fraction of the cost of a whole countertop.
Quartz doesn't need sealing, does it?
I wish we could have gotten the sink cutout but they wouldn't give it to us for some reason. (The stove cutout would also have been nice.) Note that they do not make good chopping boards, though--it's too hard and will dull your knife.
One other thing about Corian and quartz--the material is uniform. With Corian we can buff out surface damage. I don't know what you need to do the same thing with quartz.
Note that a thinner version of Corian also exists for shower enclosures, our builder would not do it, though. We have cultured marble there instead--it's more delicate but held up ok but if it were damaged you can't buff it out.
