Yes, we often have different materials and colors on the islands of our projects. There are so many options that will look good. You could contrast with a dark almost solid colored granite or even a silestone product or you could use a light granite with a tight pattern that repeats some of the colors of your marble. You cn also paint or stain your island cabinetry a different color then the main cabinets.

I suggest you browse the houzz.com kitchens for photos of combinations that you like and then look or something similar.

Hi Sheila, consider soapstone in one of it's darker incarnations. It will look both classic and cool with whichever marble you select.

There are advantages/disadvantages to marble and granite. First of all, I have to say, I would use natural stone and not one of the engineered ones if your budget is allowing it. I love marble islands and we have sold many in the 10 years we have been in business with letting customers know about the pros/cons. Marble islands are great because they are very delicate and contrary to belief not as porous as granite. They are the hardest natural stone out there. However, marbles react to acids. Acids etch them. And we have many natural acids in the kitchen (lemons, acidic drinks etc). That's why we suggest a HONED finished rather than a POLISHED if you actually cook in your kitchen. HONED finishes will not have a shine, so acids will not eat away the polish. Still you cannot let things sit there if they are acidic. Marbles are also great if you bake since they are cooler than granites.
Granites are very durable in kitchen in the sense that they do not react to many things we use in the kitchen. However, some like Santa Cecilia etc will absorb oils and water even sealed... and I do not like them for baking, as your dough will stick to them.

I like all white kitchen, so definitely support you Calcutta and Carrera decisions. Let me know if you have any questions.