Granite will not fade over time. It's been sitting around in the earth for millions of years, so a decade or 2 in your kitchen isn't going to do anything extreme enough to make it fade. The surface of granite is not affected by the UV rays of the sun, which makes it perfect for outdoor kitchen spaces in direct sunlight.
Quartz is a different story.
The resin in quartz countertops can fade when exposed to direct sunlight over several years, so you might find that your kitchen countertop starts to look a little faded as the years go by.
However, modern windows are fitted with UV-filtering qualities that should block out the harmful UV rays of the sun, allowing your indoor quartz counters to resist fading. If your kitchen windows are old, you should probably upgrade them before getting a quartz counter installed.