How to change the output of custom posts from the category on the tags?

I found a similar record output function for custom posts:
(in functions.php)

function get_related_posts( $taxonomy = '', $args = array() ){
/*
 * Before we do anything and waste unnecessary time and resources, first check if we are on a single post page
 * If not, bail early and return false
 */
if ( !is_single() )
    return false;

/*
 * Check if we have a valid taxonomy and also if the taxonomy exists to avoid bugs further down.
 * Return false if taxonomy is invalid or does not exist
 */
if ( !$taxonomy ) 
    return false;

$taxonomy = filter_var( $taxonomy, FILTER_SANITIZE_STRING );
if ( !taxonomy_exists( $taxonomy ) )
    return false;

/*
 * We have made it to here, so we should start getting our stuff togther. 
 * Get the current post object to start of
 */
$current_post = get_queried_object();

/*
 * Get the post terms, just the ids
 */
$terms = wp_get_post_terms( $current_post->ID, $taxonomy, array( 'fields' => 'ids') );

/*
 * Lets only continue if we actually have post terms and if we don't have an WP_Error object. If not, return false
 */
if ( !$terms || is_wp_error( $terms ) )
    return false;

/*
 * Set the default query arguments
 */
$defaults = array(
    'post_type' => $current_post->post_type,
    'post__not_in' => array( $current_post->ID),
    'tax_query' => array(
        array(
            'taxonomy' => $taxonomy,
            'terms' => $terms,
            'include_children' => false
        ),
    ),
);

/*
 * Validate and merge the defaults with the user passed arguments
 */
if ( is_array( $args ) ) {
    $args = wp_parse_args( $args, $defaults );
} else {
    $args = $defaults;
}

/*
 * Now we can query our related posts and return them
 */
$q = get_posts( $args );

    return $q;
}

In my template single-color, I’m calling my function

<div class="similar">
<h2 class="similar-h2">colors</h2>
<?php 
if ( function_exists( 'get_related_posts' ) ) {
    $related_posts = get_related_posts( 'colors_tax', array( 'posts_per_page' => 5,  'orderby' => 'rand') );
    if ( $related_posts ) {
        foreach ( $related_posts as $post ) {
            setup_postdata( $post ); 
?>
    <div class="sim-col1">
        <figure class="i-bot-similar">                    
            <a href="<?php the_permalink(); ?>" rel="nofollow"> 
                <?php the_post_thumbnail(array(244,244,true)); ?>
            </a>            
        </figure>
        <h3 class="no-m"><a href="<?php the_permalink(); ?>" rel="nofollow"> <?php the_title();?></a></h3>
        <strong class="sim-strong"><a href="<?php the_permalink(); ?>" rel="nofollow"> <?php echo $ncolors; ?></a></strong>
    </div>
<?php
        }
        wp_reset_postdata();
    }
}
?>

It’s work for category. How to change the output of custom posts from the category on the tags?