Can you give us more specifics? Silestone alone has like 7 colors that could be characterized as dark brown, and they are all different. Do you have the name of the quartz, and if not, can you take a picture? When you say classic white, are you referring to a specific paint color (I see Sherwin Williams has a Classical White that isn't very white at all), or are we just supposed to understand what that means (I don't; again, pics would be helpful).

It is really hard to judge the nuances of various whites from photos on a monitor. I would think that something like SW Simply White would look better with the brown, but I can't say how it would look with your trim. Samples of the colors that you can look at in your house are the best way to judge.

Edited to correct Simply White from "Simple White"

If your floor(white) looks good & chairs it should be fine. 50 shades of white or gray paint. What color are your walls? If walls are tan a cream would work. Green walls would be pretty with cream cabinets.

what is that color that's on the island?

alabaster is pretty creamy. is that what's on the island? alabaster will look like that and it makes your white flooring very blue against it.

does it have to be SW?

White dove is very popular for kitchen cabinets

Before I'd paint, I'd be asking myself a bunch of questions. Do you love the layout, the flooring, the tops etc. How long will you be in the house. What is the flooring in the remainder of the house.......

Paint is often the magic bullet, and sometimes..it is not.

Thanks! The layout won’t change. Too much investment. The flooring will be replaced next summer. Likely hardwood. We are moving in five a few years. We would like to paint the cabinets one color and the island another. Quartz counters are new. Dark brown.