Color picker interface.

Provides an interface to navigate colors and submits a 6-character hex code (with the hash mark), e.g. `#ffffff`. This field uses the WordPress core color picker introduced in WordPress 3.5.

1. Example 1: Basic Colorpicker

   This screenshot is the expanded view.

   $fm = new Fieldmanager_Colorpicker( array(
   	'name' => 'basic_colorpicker',
   ) );
   $fm->add_meta_box( 'Basic Colorpicker', 'post' );