Thanks for posting a photo, that really helps. With your kitchen being u-shape and smaller in size I would avoid very much pattern in your stone, it will look very busy. A light color like Colonial White will make the kitchen appear bigger. Since you have very little natural light you may want to avoid dark colors. I think granite or quartz are both fine as long as you like the look of the stone. "Heavy" or "Light" is more about the pattern and color not the type of stone.
I just re-did my kitchen and it is very helpful to go to a local stone yard in person and look at the full slabs of stone before making a final decision. Even if you don't buy from them, you can get a better idea of the choices. The stone can look very different from the small samples in a showroom. I did this and ended up going in a totally different direction for my kitchen counters, different stone type and color. SO glad I did this! Be sure to take a sample of your paint, cabinet, backsplash and flooring (if you can).
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White Springs Granite
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