In one program, as a proof of concept, monkeypatch

use Tk;
use Tk::DialogBox;
use Tk::Wm;
## overrides
sub Tk::Wm::Pancake { ... }
sub Tk::DialogBox::Syrup  { ... }
[download]

If it works, and you want to share with other programs, subclass, see Tk::mega and ?node_id=3989;BIT=Construct%20Tk%3A%3AWidget;HIT=tk

package Tk::JoyDialogBox;
use Tk::widgets qw/ DialogBox /;
use base qw/ Tk::DialogBox /;
Construct Tk::Widget 'JoyDialogBox';
sub Pancake { ... }
sub Syrup { ... }
[download]