I have created a toggle button css as below
.onoffswitch .ui-slider-switch {height:25px; width:80px !important;background-color: #aaaaad !important;border-color: #aaaaad }
.onoffswitch .ui-slider-label { font-size:12px; }
.onoffswitch .ui-btn-f {height:21px !important;background-color: #353537 !important; border-color:#353537 !important;}
It works at design time but reverts back runtime. See screenshots below..