shazdeh

This plugin adds an option page where you can add color options and the plugin hooks this elements to the Customizer where your client or theme users can customize the design.
Since 0.2 the custom designed panel to change colors is removed and now design tweaks are done through the WordPress Theme Customizer.

Color Manager

Enable your clients or theme users to easily change the color scheme of your design. With live preview!

ghuger

richardgabriel

Hal Gatewood

Finally a cool way to display color palettes on your site. This tiny little plugin gives you a cool way to display color palette on your pages.
Example of what it looks like: 
http://halgatewood.com/palettes/
Use the shortcode to and pass in a list of colors:
<pre><code>[awe_palette colors="434858,5886c5,#f2674a,c6006d"]
</code></pre>
Or you can call it directly with PHP in your theme:
<pre><code><?php awesome_color_palettes( array('#cccccc', 'efefef', '666') ); ?>
</code></pre>
You can include the # or not, it doesn’t care what you do.
Wait, there’s more. Create an <code>awesome-color-palette.php</code> file and put it in your theme folder and you can custom palettes for whatever you need.
It can handle 10 colors out of the box. To add more, simply create some CSS like below and add it to your style.css file in your theme.
<pre><code>.awe-color-palette.count-20 .color { width: 5%; }
</code></pre>

Awesome Color Palettes

A cool way to display color palettes on your WordPress site.

Color Manager vs Awesome Color Palettes