Regarding colors and designs, kitchen islands can be made from a number of different materials. The framework is usually wood, but the main visible surfaces could be metal or even stone - granite is a popular substance used for counter tops. Stainless steel is also good, but try to avoid aluminum if possible, because that is very soft and easily cut and scratched, and the metal oxidizes to a dull finish.
Countertop material for the island doesn't have to match the rest of your kitchen countertops as long as it is harmonious with the room's overall design. You may want to splurge on solid surfacing here, for example, and use laminate on the other countertops. A butcher-block countertop is ideal for chopping, while granite or marble works well for baking purposes and for rolling pastry dough.
Islands can "float" as well. Smaller islands used primarily as an aid in cooking or baking can be fitted with wheels and moved around the kitchen as needed to aid in cooking. Whether you consider a floating island will probably depend on what you have installed on the floor now, or plan to install (a soft wood will be nicked and scratched).
Safety First! You are better off without it if you are using up all the free space in the room. Your kitchen should be spacious and you should never feel restricted in your movement - in fact it can be dangerous if you are. Yes, a kitchen island is good to have, but not if your safety and freedom of movement are compromised to accommodate it.
small kitchen island furniture
kitchen island with seating
kitchen island deck