Remove the window valance. Will you be repainting the walls?

Remove the 4 ceiling light fixtures in the kitchen area. they are too much for the space. Instead just have recessed lighted, no fixture.

If that was my space, I'd use a grout painting product to match the tile to minimize the high contrast grout if the tile needs to remain. The glam lighting fixtures seem incongruous in a kitchen so I'd simplify all those (the four ceiling lights could easily be changed to pot lights). While there's not a measured floor plan posted, if those are 12" tiles, then the aisles widths around the furniture piece island look especially tight so I'd remove that island altogether. Double islands aren't right for this size or style space. I'd store the extra chairs elsewhere instead of having a line of furniture along the wall or use one at the kitchen desk instead of the office style chair.

Fix the grout, get new light fixtures, replace the valence with something lighter colored and more elegant (sheer curtains, Roman shades?) Paint the walls a more current color.

Agree with comments to paint, remove valance, recessed lighting & do something about the dark grout. . I would get new art & perhaps a larger green live plant on the thermostat wall.

All good suggestions. I'd add a rug under the dining table and some colorful accessories, like a new table runner. I'd paint the walls, trim and doors all the same color.

Also, where is the refrigerator? And what happened to the floor at the end of the island?