diff --git a/__tests__/demo/demo.js b/__tests__/demo/demo.js
index 0dbdbc8a..f281eda8 100644
--- a/__tests__/demo/demo.js
+++ b/__tests__/demo/demo.js
@@ -53,116 +53,139 @@ import {
 } from './demo-components';
 import { createRoot } from 'react-dom/client';
 import { I1353, I1941, I122 } from './demo-components/RemoteData';
+import { Switch, FormControlLabel, CssBaseline } from '@mui/material';
 
 module.hot.accept();
 
 const container = document.querySelector('#app');
 const root = createRoot(container); // createRoot(container!) if you use TypeScript
-root.render(
-  <StrictMode>
-    <StyledEngineProvider injectFirst>
-      <ThemeProvider theme={createTheme()}>
-        <h1>DetailPanelRemounting</h1>
-        <DetailPanelRemounting />
-        {/* <h1>Switcher</h1>
-    <DataSwitcher />
 
-  <h1>SelectionOnRowClick</h1>
-  <SelectionOnRowClick />
+function Demo() {
+  const [darkMode, setMode] = React.useState(false);
+  return (
+    <StrictMode>
+      <StyledEngineProvider injectFirst>
+        <ThemeProvider
+          theme={createTheme({
+            palette: { mode: darkMode ? 'dark' : 'light' }
+          })}
+        >
+          <CssBaseline />
+          <FormControlLabel
+            control={
+              <Switch
+                checked={darkMode}
+                onChange={(e) => {
+                  setMode(e.target.checked);
+                }}
+              />
+            }
+            label="Dark Mode"
+          />
 
-    <h1>EventTargetErrorOnRowClick</h1>
-    <EventTargetErrorOnRowClick
-      onSelectionChange={(d) => console.log('onSelectionChange', d)}
-    />
+          <h1>DetailPanelRemounting</h1>
+          <DetailPanelRemounting />
+          {/* <h1>Switcher</h1>
+  <DataSwitcher />
 
-    <h1>DetailPanelIssuesProgrammaticallyHidingWhenOpen</h1>
-    <DetailPanelIssuesProgrammaticallyHidingWhenOpen />
+<h1>SelectionOnRowClick</h1>
+<SelectionOnRowClick />
 
-    <h1>Basic</h1>
-    <Basic />
+  <h1>EventTargetErrorOnRowClick</h1>
+  <EventTargetErrorOnRowClick
+    onSelectionChange={(d) => console.log('onSelectionChange', d)}
+  />
 
-    <h1>Basic Ref</h1>
-    <BasicRef />
+  <h1>DetailPanelIssuesProgrammaticallyHidingWhenOpen</h1>
+  <DetailPanelIssuesProgrammaticallyHidingWhenOpen />
 
-    {/*
-    <h1>Export Data</h1>
-    <ExportData />
-    */}
-        {/*
-   <h1>Custom Export </h1>
-   <CustomExport />
-   */}
-        <h1>Bulk Edit</h1>
-        <BulkEdit />
-        <h1>Default Order Issue</h1>
-        <DefaultOrderIssue />
-        <h1>Bulk Edit With Detail Panel</h1>
-        <BulkEditWithDetailPanel />
-        <h1>Hiding Columns</h1>
-        <HidingColumns />
-        <h1>TestingNewActionHandlersProp</h1>
-        <TestingNewActionHandlersProp />
-        <h1>Editable Rows</h1>
-        <EditableRow />
-        <h1>One Detail Panel</h1>
-        <OneDetailPanel />
-        <h1>Multiple Detail Panels</h1>
-        <MultipleDetailPanels />
-        <h1>Editable</h1>
-        <EditableCells />
-        <h1>Frankenstein</h1>
-        <FrankensteinDemo />
-        <h1>Resizable Columns</h1>
-        <Resizable />
-        <h1>Persistent Groupings</h1>
-        <PersistentGroupings persistentGroupingsId="persistence-id" />
-        <h1>Persistent Groupings Same ID</h1>
-        <PersistentGroupings persistentGroupingsId="persistence-id" />
-        <h1>Persistent Groupings unshared</h1>
-        <PersistentGroupings persistentGroupingsId="some-other-id" />
-        <h1>Tree data</h1>
-        <TreeData />
-        <h1>Table with Summary Row</h1>
-        <TableWithSummary />
-        <h1>
-          Table with custom numbers of pages around current page in stepped
-          navigation
-        </h1>
-        <TableWithNumberOfPagesAround />
-        <h1>Fixed Column with Row Edits</h1>
-        <FixedColumnWithEdit />
-        <h1>Localization with Custom Components</h1>
-        <LocalizationWithCustomComponents />
-        <h1>Remote Data Related</h1>
-        <ol>
-          <li>
-            <h3>
-              mbrn{' '}
-              <a href="https://github.com/mbrn/material-table/issues/1353">
-                #1353
-              </a>
-            </h3>
-            <I1353 />
-          </li>
-          <li>
-            <h3>
-              mbrn{' '}
-              <a href="https://github.com/mbrn/material-table/issues/1941">
-                #1941
-              </a>
-            </h3>
-            <I1941 />
-          </li>
-          <li>
-            <h3>
-              <a href="https://github.com/material-table-core/core/issues/122">
-                #122
-              </a>
-            </h3>
-            <I122 />
-          </li>
-        </ol>
-      </ThemeProvider>
-    </StyledEngineProvider>
-  </StrictMode>
-);
+  <h1>Basic</h1>
+  <Basic />
+
+  <h1>Basic Ref</h1>
+  <BasicRef />
+
+  {/*
+  <h1>Export Data</h1>
+  <ExportData />
+  */}
+          {/*
+ <h1>Custom Export </h1>
+ <CustomExport />
+ */}
+          <h1>Bulk Edit</h1>
+          <BulkEdit />
+          <h1>Default Order Issue</h1>
+          <DefaultOrderIssue />
+          <h1>Bulk Edit With Detail Panel</h1>
+          <BulkEditWithDetailPanel />
+          <h1>Hiding Columns</h1>
+          <HidingColumns />
+          <h1>TestingNewActionHandlersProp</h1>
+          <TestingNewActionHandlersProp />
+          <h1>Editable Rows</h1>
+          <EditableRow />
+          <h1>One Detail Panel</h1>
+          <OneDetailPanel />
+          <h1>Multiple Detail Panels</h1>
+          <MultipleDetailPanels />
+          <h1>Editable</h1>
+          <EditableCells />
+          <h1>Frankenstein</h1>
+          <FrankensteinDemo />
+          <h1>Resizable Columns</h1>
+          <Resizable />
+          <h1>Persistent Groupings</h1>
+          <PersistentGroupings persistentGroupingsId="persistence-id" />
+          <h1>Persistent Groupings Same ID</h1>
+          <PersistentGroupings persistentGroupingsId="persistence-id" />
+          <h1>Persistent Groupings unshared</h1>
+          <PersistentGroupings persistentGroupingsId="some-other-id" />
+          <h1>Tree data</h1>
+          <TreeData />
+          <h1>Table with Summary Row</h1>
+          <TableWithSummary />
+          <h1>
+            Table with custom numbers of pages around current page in stepped
+            navigation
+          </h1>
+          <TableWithNumberOfPagesAround />
+          <h1>Fixed Column with Row Edits</h1>
+          <FixedColumnWithEdit />
+          <h1>Localization with Custom Components</h1>
+          <LocalizationWithCustomComponents />
+          <h1>Remote Data Related</h1>
+          <ol>
+            <li>
+              <h3>
+                mbrn{' '}
+                <a href="https://github.com/mbrn/material-table/issues/1353">
+                  #1353
+                </a>
+              </h3>
+              <I1353 />
+            </li>
+            <li>
+              <h3>
+                mbrn{' '}
+                <a href="https://github.com/mbrn/material-table/issues/1941">
+                  #1941
+                </a>
+              </h3>
+              <I1941 />
+            </li>
+            <li>
+              <h3>
+                <a href="https://github.com/material-table-core/core/issues/122">
+                  #122
+                </a>
+              </h3>
+              <I122 />
+            </li>
+          </ol>
+        </ThemeProvider>
+      </StyledEngineProvider>
+    </StrictMode>
+  );
+}
+root.render(<Demo />);
diff --git a/src/components/MTableHeader/index.js b/src/components/MTableHeader/index.js
index 37fb7930..4414b34f 100644
--- a/src/components/MTableHeader/index.js
+++ b/src/components/MTableHeader/index.js
@@ -566,8 +566,7 @@ export const styles = {
   header: {
     // display: 'inline-block',
     // position: 'sticky',
-    top: 0,
-    backgroundColor: 'background.paper' // Change according to theme,
+    top: 0
   },
   headerWrap: (alignRight) => ({
     display: 'flex',