Congrats on the new home! Quartz is a bit more "neutral" than granite as it is more monochromatic with much less movement. Caesarstone has some nice grey colors that might go well with your cream cabinets, also some brown colors as well.

There are also Quartz counters that are doing a decent job of mimicking marble, if you need a more traditional look. Below is a shot from a house we designed last year with a simulated marble island.

If you wanted something very unique, the Black Mosaic Gold Granite goes very well with soft green and off white. It has orange/ brown elements as well:

For a softer look you could go with a Leathered (textured and matte finish) Antique Brown Granite (which is actually black):

or a soft, lilting white stone like River Valley Granite:

Depending on the exact green you use, a Costa Esmerelda Granite might be a elegant and understated look that would go well with your antiques:

Lastly, have you considered soapstone? It's a great way to have a contemporary blended with historic look. It looks great in homes with lots of character.

I vote quartz! I didn't even know there were any other options than granite until we bought our house :) It's a 150 year old farmhouse, gut rehab, and when the seller designed the kitchen he wanted the style to be consistent with the age/look of the house. So it sounds like kind of what you're going for? He used white cabinets and white quartz countertops. I absolutely love the look of the kitchen. The only drawback is that it's difficult to keep light colored quartz clean. If you want something that hides spots and splashes better, maybe granite is the option for you...otherwise, I'd pick quartz. I'm attaching a pic of my kitchen so you can see what the counter looks like...as you can see the color is very uniform.

I agree with the comments above. I would say that the type of material you do is really a personal preference, and depends on what your goals are. Manufactured materials (quartz) are less maintenance and fuss, but cannot quite give you the look of the real thing. People typically prefer granite one way or the other i.e. movement or granular.

I agree with Granite Grannies that Costa Esmeralda would be a very nice look especially in a satin (leather) or honed finish. For your application I would definitely look into these finishes regardless of the material you select. If the material does not come that way from the factory, you can always have your fabricator create it for you.

Soap stone would be really nice too, as long as you aren't going to be fussy about it scratching and showing a lot. It is easy to buff, but really that's just part of the look.

Another option could be something like the picture below with a slight greenish hue, but a lot of neutrals to work with.

Actually maybe you can't see how uniform the color is from the photo I posted...for some reason it looked better on my computer...sorry about that!