In order to brighten things up, look at the off whites. They look like colors on the little sample cards, but when painted on the wall, often look more like a pale color than a white. I'd go all the way up to the lightest colors. I really don't see how you can go wrong, your choices so far are so neutral. I think you could go warmer, or cooler, and it would make sense.

In order to brighten up the space, I would do these things:

-think about shiny, beefy drawer pulls/knobs, like polished nickel

-think about maybe glass subway tile (or other pattern), or even a metallic tile. Something that reflects light.

-make sure your lighting is excellent in every regard: overhead, undercabinet, pendant work lights. That will really help.