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!

SAID ASSEMLAL

Generates Custom popups for any part of your post’s content
<ul>
<li>Works perfectly on all +3 wordpress versions</li>
<li>Full options ( Custom width, custom labels )</li>
<li>Responsive ( Thanks to fancybox’s jQuery plugin )</li>
</ul>

PopupThis

Generates Custom popups for any part of your post's content

Gameplorer`s WPColorBox vs PopupThis