Use selected icons for settings editor as needed.

packages/settingeditor/style/base.css

@@ -240,3 +240,66 @@
 #setting-editor .jp-SettingsTableEditor td.jp-SettingsTableEditor-type {
   text-align: right;
 }
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-FileIcon {
+  background-image: var(--jp-icon-file-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-TextEditorIcon {
+  background-image: var(--jp-icon-text-editor-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-NotebookIcon {
+  background-image: var(--jp-icon-notebook-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-FolderIcon {
+  background-image: var(--jp-icon-folder-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-CodeConsoleIcon {
+  background-image: var(--jp-icon-console-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-MarkdownIcon {
+  background-image: var(--jp-icon-markdown-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-LauncherIcon {
+  background-image: var(--jp-icon-launcher-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-SettingsIcon {
+  background-image: var(--jp-icon-settings-selected);
+}
+
+#setting-editor
+  .jp-PluginList
+  .jp-mod-selected
+  .jp-PluginList-icon.jp-KeyboardIcon {
+  background-image: var(--jp-icon-keyboard-selected);
+}