Please be clear from next time before posting the query!
Here you go:
protected void DataGrid_ItemDataBound(object sender, DataGridItemEventArgs e)
CheckBox cbx = (CheckBox)e.Row.FindControl("checkBoxID");
if (cbx != null)
e.Row.BackColor = System.Drawing.Color.Red;
Lastly, please read a book! Doing Google would had given you the difference of events immediately!