enabling row selection

In my grid ,after applying my own skin, color change is not happening for selected row.Please let me know how can i achieve this

After using setSkin all colors must be adjusted according to skin related styles.
Selected row color described as

div.gridbox_[SKINNAME] table.obj tr.rowselected td{
background-color:whitesmoke;
color:black;
}

If problem still occurs - please provide custom css used in your case.