HTML - Datalist: posicionarse según las primeras letras

<input type="text" name="favorite_color" list="colors" placeholder="Enter a color">

  <datalist id="colors">

   <option value="Blue">

   <option value="Brown">

   <option value="Cyan">

   <option value="Green">

   <option value="Orange">

   <option value="Pink">

   <option value="Purple">

   <option value="Red">

   <option value="Yellow">

  </datalist>

<input type="text" list="colors" name="favorite_color" list="colors" placeholder="Enter a color">

  <datalist id="colors">

   <option value="Blue">

   <option value="Brown">

   <option value="Cyan">

   <option value="Green">

   <option value="Orange">

   <option value="Pink">

   <option value="Purple">

   <option value="Red">

   <option value="Yellow">

  </datalist>

let string = "am";

let options = ['amarillo', 'azul', 'rojo'];

let optionSearcher = (string) => {

  let arr = [];

  for (let option of options) {

    if (option.startsWith(string)) arr.push(option);

  } return arr;

}

console.log(optionSearcher(string));