Display 2 different custom taxonomy terms on single product page

Our WooCommerce products have two custom taxonomies: sizes and colors.

I’m trying to display the custom toxonomy terms for a product on its single product page. I’m using the woocommerce_single_product_summary action hook. I can’t get both taxonomies to display at the same time.

Here’s my code so far:

<?php
/**
 * display a woocommerce product's custom taxonomy terms on single product pages
 */

function display_single_product_sizes_after_summary() { 
    global $post;
	
    $size_terms = get_the_terms( $post->ID , array( 'sizes') );
	// begin creating html markup
	$size_markup = '';
	if(!empty($size_terms)) {
		$size_markup .= "<p>Similar size shades: ";
	}
	// init counter
	$is = 1;
	foreach ( $size_terms as $size_term ) {
		$size_markup .= '<a href="/shades/size/' . $size_term->slug . '">' . $size_term->name . '</a>';
		//  Add comma (except after the last item)
		$size_markup .= ($is < count($size_terms))? ", " : "";
		// Increment counter
		$is++;
		//finish the markup
	    if(!empty($size_terms)) {
			$size_markup .= "</p>";
		}
	}
	echo $size_markup;
};

function display_single_product_colors_after_summary() { 
    global $post;
	
    $color_terms = get_the_terms( $post->ID , array( 'colors') );
	// begin creating html markup
	$color_markup = '';
	if(!empty($color_terms)) {
		$color_markup .= "<p>Similar color shades: ";
	}
	// init counter
	$ic = 1;
	foreach ( $color_terms as $color_term ) {
		$color_markup .= '<a href="/shades/color/' . $color_term->slug . '">' . $color_term->name . '</a>';
		//  Add comma (except after the last item)
		$color_markup .= ($ic < count($color_terms))? ", " : "";
		// Increment counter
		$ic++;
		//finish the markup
		if(!empty($color_terms)) {
			$color_markup .= "</p>";
		}
	}
	echo $color_markup;
};

function display_single_product_terms_after_summary() {
	display_single_product_sizes_after_summary();
	display_single_product_colors_after_summary();
};
add_action( 'woocommerce_single_product_summary', 'display_single_product_terms_after_summary', 101, 0 );
?>

This outputs the following:

Similar size shades: Small

Similar color shades:

If I reverse the order of the two sub-functions in display_single_product_traits_after_summary the output changes to:

Similar color shades: Blue

Similar size shades:

I’ve tried to use a reset at the end of each subfunction. I’ve tried:

	echo $size_markup;
	wp_reset_postdata();

and:

	echo $color_markup;
	wp_reset_postdata();

This makes no difference.

I’ve also tried:

	echo $size_markup;
	rewind_posts();

and:

	echo $color_markup;
	rewind_posts();

This breaks the page altogether.

What is my mistake here, and how can I get the terms from both taxonomies to display?