if you don't care about IE8, you can do:
HTML:
CSS:
.cb_wrap{
position: relative
}
input{
opacity: 0;
position: relative;
z-index: 10;
}
.cb_dummy{
position: absolute;
top: 0;
left: 0;
z-index: 0;
width: 15px;
height: 15px;
background: #f00; /* use some image */
}
input:checked + .cp_dummy{
background: #0f0; /* use some image */
}
Demo: http://jsfiddle.net/FKqj3/