You can manually set the relelements you want to group when you call colorbox:
$('a[rel="example1"]').click(function(event){
event.preventDefault();
$.colorbox({
href: $(this).attr('href'),
maxWidth: '90%',
initialWidth: '200px',
initialHeight: '200px',
speed: 700,
overlayClose: false,
rel: $(this).attr('rel')
});
});
Edit
colorbox, , , , , rel, colorbox. , ... :
$('a[rel="example1"]').click(function(event){
event.preventDefault();
$('a[rel="example1"]').colorbox({
maxWidth: '90%',
initialWidth: '200px',
initialHeight: '200px',
speed: 700,
overlayClose: false
});
$.colorbox({
href: $(this).attr('href')
});
});