Spraying might not last long if they are touched daily. Another option is to get them plated by finding a local metal plating shop. Bring a sample to a local shop and they will tell you if it can be done and how much it will be.

I had a few bathroom accessories plated about ten years ago when I lived in LA, and the price was very reasonable.

I'd try paint remover: the citrus stuff first. Alternatives are lacquer thinner or denatured alcohol. That looks like the applied finish coming off.

Have you considered buying new ones?

The style of the pulls is very Mediterrean. Is that style still appropirate for your kitchen cabinets and overall appearance?

Could you please post the two pulls together so we can see the difference?

When DH cleaned up our antique doorknobs, he put them in an old crock pot overnight with water and liquid laundry soap. Cleaned them right up but also removed the finish, which was our intent and may not be yours.