Decide how the call custom popup instead of colorbox

Currently colorbox is called if available but nothing else.

                if ($.colorbox) {
                    $.colorbox({html: $block.html()});
                }

How should the block become visible?

We can require the theme to have a public function ie cbb_callback but that would limit the block visibility to appear in one way. It would be better to have this on a block specific configuration.