PHP - Get placeholder for Lazyload

placeholder.php

<?php
/**
 * Image placeholder
 *
 * @param  integer $width  Placeholder width.
 * @param  integer $height Placeholder height.
 * @param  string  $color  Placeholder color.
 * @return string          Data ULR
 */
function get_placeholder(int $width = 0, int $height = 0, string $color = 'transparent') {
  $color = rawurlencode((string) $color);
  return 'data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 width=%22' . $width . 'px%22 height=%22' . $height . 'px%22 viewBox=%220 0 ' . $width . ' ' . $height . '%22%3E%3Crect x=%220%22 y=%220%22 width=%22' . $width . '%22 height=%22' . $height . '%22 fill=%22' . $color . '%22%3E%3C/rect%3E%3C/svg%3E';
}
?>

<img src="<?php echo get_placeholder(2210, 3315, '#ff0000'); ?>" data-src="https://picjumbo.com/wp-content/uploads/cute-dog-reading-book-2210x3315.jpg" class="js-lazyload">