function isValidHexColor(color) {
  const hexColorRegex = /^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$/;
  return hexColorRegex.test(color);
}

// Example usage:
// console.log(isValidHexColor("#FF0000")); // true
// console.log(isValidHexColor("#F00"));    // true
// console.log(isValidHexColor("#GG0000")); // false
// console.log(isValidHexColor("red"));     // false