Is there electric in the island? If so, perhaps the least intrusive option would be to add some strip lighting under the island countertop overhang. Inadequate light can make a dark finish seem even darker. I can't tell from the photo whether it is black paint or very dark stain, but the lighting will help more if it is stained because it will help bring out variations in the wood.

Or changing your perimeter countertops to something darker. The contrast seems very stark because your perimeter is so neutral. Adding more dark elements to other areas will help make the contrast look more natural.

If you really don't like the two finishes together, decide which one you like better and have the other refinished. However, I do see the dark/black island with cream/off-white cabinetry perimeter very often, and I think the key to uniting the two is careful countertop selection.