<Excalidraw
  onDuplicate={(elements, prevElements) => {
    const prevElementsMap = arrayToMap(prevElements);
    return elements.map((el) => ({
      ...el,
      backgroundColor: !prevElementsMap.has(el.id)
        ? el.backgroundColor === "red"
          ? "yellow"
          : "red"
        : el.backgroundColor,
    }));
  }}
/>