Where is the responsible CSS definition where I could change the disc color of a linked list item? I can't find it.
Working example: http://jsfiddle.net/Gajotres/vMCKD/
.ui-listview .ui-btn .ui-btn-inner .ui-icon-arrow-r {
background-color: red !important;
}
You can replace .ui-listview with an id of your listview, so that this change can only affect certain listview/s.