Dojo Digital

This plugin adds a textarea to the Customize page that allows theme editors to write, preview, and implement CSS code in real time. 
It also includes a frontend CSS editor window with live preview capability.

Live CSS Preview

Live front-end and Customizer CSS editing powered by native WordPress Additional CSS storage.

Brian Harris

This plugin adds support for the Twenty Fourteen theme to the <a href="https://wordpress.org/extend/plugins/styles">Styles plugin</a>.
Features of the plugin
<ul>
<li>Instant previews</li>
<li>Text size</li>
<li>Google Fonts</li>
<li>Text colors</li>
<li>Border colors</li>
<li>Background colors</li>
<li>Hundreds of options</li>
<li>Consistent interface and names in every theme</li>
<li>Built on WordPress customizer, so Styles grows as WordPress grows</li>
</ul>
Styles and options for all built-in WordPress themes are free. More themes are available at <a href="http://stylesplugin.com" rel="nofollow ugc">StylesPlugin.com</a>.
Contact
<ul>
<li><a href="http://wpdefault.com/forums/forum/styles-twentyfourteen/" rel="nofollow ugc">Get support</a></li>
</ul>

Styles: TwentyFourteen

Be creative with colors and fonts. Styles changes everything.

Live CSS Preview vs Styles: TwentyFourteen