I'm attaching a photo I took of new construction in my area where the builder used a similar color scheme that you describe. The countertops are "Super White,"(aka Supreme White and Fantasy White) which, as know, is a dolomitic marble. This bathroom has wood-look porcelain, white cabinets, walls are painted a blue-gray, bath / shower combo and vanity backsplash has white subway tiles. The master bathroom in this house is all marble. There are some alternative countertop materials that may work for your color scheme if you decide against engineered quartz countertops. Stained concrete is a possibility, but it will give more of an "urban" look. Natural light-gray (non-marble) stones are White Macaubus quartzite, Princess White quartzite and White Pearl quartzite. Cristallo quartzite is another option, but it's pricey and some slabs look more yellow than grey. Another option is to match the floor tiles with a charcoal brown color on the countertops - such as elegant brown quartzite or brown sequoia granite

There's a chip repair kit you can buy on amazon for like $25. I believe it works on quartz. I just used it on a marble chip in our kitchen. It is pretty miraculous and I just tested to see if my parents could spot where I did the fix, and they could not. Took about 10 minutes start to finish and was very easy. Just search "marble chip repair" and there are a couple well-reviewed options on amazon.

would be interested in if anyone installed raw concrete and their experiences with it.

We used Clamshell, which is a pale grey with some white and grey splotches. From afar it reads reads as a fairly solid grey. Up close is when you see the variation. We have had it for a year now with no maintenance complaints.