I would not introduce any more grays!

I would look at solid surface options that are beige or off white with speckles that can tie in the floor colors. Since the floor is very multicolored I would aim for a visually quiet counter, that is, not with major veins and swirls, and same idea for a single color backsplash (replace the over the range mosaic)

I would keep the counters and just change the dated backsplash.

I agree with cpartist. Save yourself some money and just do the backsplash.

Add undercounter lighting after installing new backsplash.