no photo attached.

With a dark floor, I would definitely go with lighter cabinets so that your kitchen is not dark. The same goes for your countertop and splash. Below in the first photo is a dark kitchen that is beautiful but it would not make me happy. The second kitchen has dark wall cabinets but a white island that brightens things a bit. The third photo shows dark cabinets with a light wood floor and that's the look that I would choose if I really wanted dark cabinets. Dark floors show every little thing that lands on them. Light floors do not. https://www.houzz.com/photos/dark-wood-kitchen-floor-phbr0lbl-bl~l_37099?fi=8

Yes - a lighter island countertop. That is really a nice kitchen. If you have plenty of storage, you could remove some of the upper cabinetry and either leave empty for a more open feel or replace with a small amount of open shelving. If you choose to paint, have it done professionally. That is a lot of cabinetry and it takes a patient and experienced DIY person to paint cabinets well. Keep in mind a painted cabinet, whether done DIY or by a professional, will never have the durability of a factory finished cabinet. I have wood cabinets and recently installed new quartz counters in a light white / gray / pearl design and new backsplash. I also got a white farmhouse sink and under cabinet lighting. My kitchen is very light now.

You need a kitchen designer before doing anything else. No to espresso it is a dated cabinet colour IMO. A poll has to have some info and it looks like you are just telling us you have a U shaped kitchen, We need actual information like what are the floors like in the area around the kitchen., A floor plan of the kitchen if not yet built and pics if it is. BTW if you have a U shaped kitchen unless it is huge you cannot have an island .