Highlight Current Sub-Category in Single Post

I have a photo gallery site that has images categorized as such

Weddings
-Wedding Teasers
-Wedding I
-Wedding II
-Wedding III
Events
-Event Teasers
-Event I
etc.

When you’ve viewing a certain sub-category (ie:Portrait Teasers) it is glowing the the category list above the images

https://www.leapfrogwebmarketing.com/clients/creative_expression/archives/category/portraits/portrait-teasers

but when you’ve vieweing a full image it does not work.

https://www.leapfrogwebmarketing.com/clients/creative_expression/archives/931

I got it working for only one Category (Mitzvahs) by using this bit of code, but cannot figure out how to make it work for all category / sub-categories.

https://www.leapfrogwebmarketing.com/clients/creative_expression/archives/1339

<?php if (in_category('21')){ ?>

	<?php
		$catsy = get_the_category();
		$myCat = $catsy[0]->cat_ID;
		wp_list_categories('child_of=21&orderby=order&title_li=&current_category='.$myCat');
	?>

<?php } ?>