Body field in colorbox
If you have Colorbox installed, you can install Colorbox Node &amp; Overlay which will let you create a colorbox node link with a colorbox-node class (e.g. &lt;a class="colorbox-node" href="/my/node/path"&gt;My Node&lt;/a&gt;).

In your theme's node preprocess function, you can add that class to the read more link:

/**
 * Implements hook_preprocess_node() in your theme's template.php
 */
function MYTHEME_preprocess_node(&amp;$variables) {
  if ($variables['view_mode'] == 'teaser') {
    $variables['content']['links']['node']['#links']['node-readmore']['attributes']['class'] = 'colorbox-node';
  }
}


You'll need to adjust your theme's stylesheet rules to hide the non-body fields (and other styling as necessary), but it will work.