Yes, it is possible.
To start the iCheck in one or more fields is done through the jQuery selectors. An example to apply iCheck to all checkboxes and radios with the blue theme would look like this:
$('input[type="checkbox"], input[type="radio"]').iCheck({
checkboxClass: 'icheckbox_square-blue',
radioClass: 'iradio_square-blue'
});
To select only the checkboxes and radios with the icheck class, simply include your class in the selector. For example:
$('input[type="checkbox"].icheck, input[type="radio"].icheck').iCheck({
checkboxClass: 'icheckbox_square-blue',
radioClass: 'iradio_square-blue'
});