Apply datatables styling to light theme

src/rstudio/_rstudio-light.scss

   }
 }
 
+/* Data Frame Preview */
+.dataTables_wrapper thead th {
+    background: $ui-rstudio-tabs-selected !important;
+    color: $ui-rstudio-tabs-selected-color !important;
+}
+.dataTables_scrollBody table tbody td:first-child {
+    background: $ui-rstudio-tabs-selected !important;
+    color: $ui-rstudio-tabs-selected-color !important;
+}
+.dataTables_info {
+    background: $ui-rstudio-tabs-selected !important;
+    color: $ui-rstudio-tabs-selected-color !important;
+}
+
 /* scrollbars */
 .rstudio-themes-flat .rstudio-themes-default .gwt-TabLayoutPanelTabs,
 .rstudio-themes-flat .rstudio-themes-default .rstheme_minimizedWindowObject .rstheme_center,