Dennis

There are a few ColorBox plugins available, but the most of them add inline JavaScript code 
to your site, embed the script files in the head instead at the bottom and other issues which 
impact the site performance. 
I needed something better and developed this plugin for a Blog about <a href="http://www.gameplorer.de" rel="nofollow ugc">Casual Games</a>. 
Now I decided to make it public, if you wonder about the plugins name. 🙂
Features of Gameplorer`s WPColorBox
<ul>
<li>It adds the required HTML-Code automatically to all links which point to an image.</li>
<li>It doesn’t alter your posts, just the output.</li>
<li>It enqueues the ColorBox script at the bottom of your site for a better site performance. </li>
<li>It doesn’t add any inline JavaScript code for a better site performance.</li>
<li>You can disable enqueuing of CSS and JavaScript files in the options*.</li>
<li>You can choose between 5 different UIs of ColorBox in the plugin options.</li>
<li>It automatically combines multiple images to a gallery (displays next and prev links).</li>
</ul>
* Useful if you want to enqueue it from other sources (e.g. CDN) or want to copy the code into your existing files.
See some plugin details and Screenshots on <a href="http://www.gameplorer.de/tools/wordpress-colorbox/" rel="nofollow ugc">Gameplorer.de</a>.

Gameplorer`s WPColorBox

Gameplorer`s WPColorBox adds a ColorBox effect to all of your linked images - automatically!

Ciprian Turcu

Fancybox (lightbox) fully compatible for wordpress. You can add (so far):
<ul>
<li>Image link (local or external)</li>
<li>Html content (or normal – Content hast to be added using a custom field with normal text or html content)</li>
<li>Link to another webpage (webpage content will show in iframe)</li>
</ul>
Requires JavaScript Enabled. Uses jQuery (Fancybox and TinyMce Editor). 
You can modify all settings fancybox code allows you to modify!
<a href="https://wordpress.org/extend/plugins/advanced-fancybox/faq/" rel="ugc">How to use custom fields?</a>
DONATE! 
 <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=8322585" rel="nofollow ugc">DONATE HERE</a> – (any ammount using paypal or credit card)

Advanced Fancybox

Fancybox (lightbox) fully copatible for wordpress.

Gameplorer`s WPColorBox vs Advanced Fancybox