I like this space as is -- open and airy and light and a very pleasant good mood kind of feel.

Instead of repainting, have you considered adding some trim -- wallpaper tape -- at the top of the wall throughout to both pick up the existing colors and add more color. Or choose the design to add something to personalize it to you and your interests?

You might also add color w/window treatment and chose that and the trim color and design with both of them in mind.

I think it looks beautiful as it is. I wouldn't change the wall color. It's bright, clean, and airy. The light, neutral wall color works so nicely with all the light to medium wood tones in the room.

Can't really add much about a paint color for the walls (hoping your request is for the walls and not the cabinets). BUT, it looks like a great space!!. Really love the openness while at the same time having division between the spaces.

I also think this is a great looking kitchen. You could go just a tad beige - a shade pulled out from one of the colors in the backsplash. It would help your white door trim stand out just a bit. If your cousin is a little more of a color person, both light shades of blue or green or teal - with possibly with a gray undertone. I am not sure because I would want to see a sample next to the backsplash and sometimes computer monitors don't get the colors right.