The best advice I have read on solving this problem is by Carla Aston Designed.

https://carlaaston.com/designed/oh-travertine-what-do-we-do-with-you-now

Her palettes are spot on to help update your older finishes.

I'd look at either green or white for window treatments and rugs (runners). I think anything else will either clash, emphasize the yellow (pairing it with complementary colors), or double-down on warm tones (reds and oranges).

You should be able to tone down the appearance of the yellow by changing out your light bulbs for ones with a higher color temperature. Warm white lamps at 2700 K (Kelvin) lamps are very warm in color and will emphasize the yellows. Daylight bulbs at 4000 K or higher will tone that down. If you are going to change the lamps, do it before you choose paint, rugs, and window treatments, because they will affect how it all appears.

Taking down the wood valance over the window looks like an easy way to start to de-Tuscanize the kitchen. It looks like you'd have to replace the crown molding, but it shouldn't disturb the other cabinets. Changing the central lighting fixture would also be a relatively low-cost option.