olark.configure('system.hb_custom_style', { 
	general: { 
		fonts: [''], 
		corners: 'soft', 
		secondaryColor: '' 
	} 
});

Notes

We have two options that allow you to have ‘soft’ or ‘hard’ corners for the chatbox. By default the chatbox will have soft corners.

olark.configure('system.hb_custom_style', {
  general: {
    fonts: [''],
    corners: 'hard',
    secondaryColor: ''
  }
});

corners