No matter what you choose, just be aware that when you add a layer of flooring on top of existing flooring in your kitchen it is possible to trap your dishwasher and refrigerator such that you won't be able to pull it out to service or replace it. It's more likely to happen with the dishwasher since it is trapped by the counter. Sometimes refrigerators have some wiggle room at the top. This has happened to me and one of my friends. The people laying the floor don't care because it's not their problem and their livelyhood depends on them not telling people about it.

You will get more comments on your question if you post pictures of the colors that are available for you to choose from. It's even better if you have brought samples home and can show them against your cabinets. If you're doing your whole first floor with it you need to also be thinking about how it's going to look with your furniture in the affected rooms. The one thing I will say is that gray floors are a dead trend on the coasts already. If they're still popular where you are you can expect it to be a trend that won't last much longer.