diff --git a/src/Providers.tsx b/src/Providers.tsx
index accfd85c..2093c1c5 100644
--- a/src/Providers.tsx
+++ b/src/Providers.tsx
@@ -6,7 +6,7 @@ import { Provider, Atom } from "jotai";
 import { globalScope } from "@src/atoms/globalScope";
 import createCache from "@emotion/cache";
 import { CacheProvider } from "@emotion/react";
-import ThemeProvider from "@src/theme/ThemeProvider";
+import RowyThemeProvider from "@src/theme/RowyThemeProvider";
 import SnackbarProvider from "@src/contexts/SnackbarContext";
 
 import { Suspense } from "react";
@@ -29,7 +29,7 @@ export default function Providers({
         <HelmetProvider>
           <Provider scope={globalScope} initialValues={initialAtomValues}>
             <CacheProvider value={muiCache}>
-              <ThemeProvider>
+              <RowyThemeProvider>
                 <ErrorBoundary FallbackComponent={ErrorFallback}>
                   <SnackbarProvider>
                     <Suspense fallback={<Loading fullScreen />}>
@@ -37,7 +37,7 @@ export default function Providers({
                     </Suspense>
                   </SnackbarProvider>
                 </ErrorBoundary>
-              </ThemeProvider>
+              </RowyThemeProvider>
             </CacheProvider>
           </Provider>
         </HelmetProvider>
diff --git a/src/atoms/project.ts b/src/atoms/project.ts
index bfe254b3..68277ed3 100644
--- a/src/atoms/project.ts
+++ b/src/atoms/project.ts
@@ -3,6 +3,7 @@ import { sortBy } from "lodash-es";
 import { ThemeOptions } from "@mui/material";
 
 import { userRolesAtom } from "./auth";
+import { UpdateFunction } from "./types";
 
 export const projectIdAtom = atom<string>("");
 
@@ -24,10 +25,13 @@ export type PublicSettings = Partial<{
 }>;
 /** Public settings are visible to unauthenticated users */
 export const publicSettingsAtom = atom<PublicSettings>({});
+/** Stores a function that updates public settings */
+export const updatePublicSettingsAtom =
+  atom<UpdateFunction<PublicSettings> | null>(null);
 
 /** Project settings are visible to authenticated users */
 export type ProjectSettings = Partial<{
-  tables: Array<TableSettings>;
+  tables: TableSettings[];
 
   setupCompleted: boolean;
 
@@ -42,6 +46,9 @@ export type ProjectSettings = Partial<{
 }>;
 /** Project settings are visible to authenticated users */
 export const projectSettingsAtom = atom<ProjectSettings>({});
+/** Stores a function that updates project settings */
+export const updateProjectSettingsAtom =
+  atom<UpdateFunction<ProjectSettings> | null>(null);
 
 /** Table settings stored in project settings */
 export type TableSettings = {
diff --git a/src/atoms/types.d.ts b/src/atoms/types.d.ts
new file mode 100644
index 00000000..8d85b83e
--- /dev/null
+++ b/src/atoms/types.d.ts
@@ -0,0 +1 @@
+export type UpdateFunction<T> = (update: Partial<T>) => Promise<any>;
diff --git a/src/atoms/user.ts b/src/atoms/user.ts
index bb390720..65db3bb7 100644
--- a/src/atoms/user.ts
+++ b/src/atoms/user.ts
@@ -6,6 +6,7 @@ import { ThemeOptions } from "@mui/material";
 import themes from "@src/theme";
 import { publicSettingsAtom } from "./project";
 import { TableFilter } from "./table";
+import { UpdateFunction } from "./types";
 
 /** User info and settings */
 export type UserSettings = Partial<{
@@ -32,6 +33,10 @@ export type UserSettings = Partial<{
 }>;
 /** User info and settings */
 export const userSettingsAtom = atom<UserSettings>({});
+/** Stores a function that updates user settings */
+export const updateUserSettingsAtom = atom<UpdateFunction<UserSettings> | null>(
+  null
+);
 
 /**
  * Stores which theme is currently active, based on user or OS setting.
diff --git a/src/components/Settings/ThemeColorPicker.tsx b/src/components/Settings/ThemeColorPicker.tsx
index 46bb4fb7..35e00f0c 100644
--- a/src/components/Settings/ThemeColorPicker.tsx
+++ b/src/components/Settings/ThemeColorPicker.tsx
@@ -57,7 +57,7 @@ export default function ThemeColorPicker({
             width={244}
             height={140}
             color={toColor("hex", light)}
-            onChange={(c) => () => setLight(c.hex)}
+            onChange={(c) => setLight(c.hex)}
             dark={theme.palette.mode === "dark"}
           />
 
diff --git a/src/components/Settings/UserSettings/Personalization.tsx b/src/components/Settings/UserSettings/Personalization.tsx
index 943d33a7..f6f2fc2c 100644
--- a/src/components/Settings/UserSettings/Personalization.tsx
+++ b/src/components/Settings/UserSettings/Personalization.tsx
@@ -33,7 +33,7 @@ export default function Personalization({
       <FormControlLabel
         control={
           <Checkbox
-            checked={customizedThemeColor}
+            defaultChecked={customizedThemeColor}
             onChange={(e) => {
               setCustomizedThemeColor(e.target.checked);
               if (!e.target.checked) {
@@ -50,7 +50,7 @@ export default function Personalization({
       />
 
       <Collapse in={customizedThemeColor} style={{ marginTop: 0 }}>
-        <Suspense fallback={<Loading />}>
+        <Suspense fallback={<Loading style={{ height: "auto" }} />}>
           <ThemeColorPicker
             currentLight={settings.theme?.light?.palette?.primary?.main}
             currentDark={settings.theme?.dark?.palette?.primary?.main}
diff --git a/src/components/Settings/UserSettings/Theme.tsx b/src/components/Settings/UserSettings/Theme.tsx
index d639ceb1..de719c32 100644
--- a/src/components/Settings/UserSettings/Theme.tsx
+++ b/src/components/Settings/UserSettings/Theme.tsx
@@ -58,7 +58,7 @@ export default function Theme({
       <FormControlLabel
         control={
           <Checkbox
-            checked={Boolean(settings.theme?.dark?.palette?.darker)}
+            defaultChecked={Boolean(settings.theme?.dark?.palette?.darker)}
             onChange={(e) => {
               updateSettings({
                 theme: merge(settings.theme, {
diff --git a/src/hooks/useFirestoreDocWithAtom.ts b/src/hooks/useFirestoreDocWithAtom.ts
index 014ade85..2322f423 100644
--- a/src/hooks/useFirestoreDocWithAtom.ts
+++ b/src/hooks/useFirestoreDocWithAtom.ts
@@ -1,17 +1,19 @@
 import { useEffect } from "react";
 import { useAtom, PrimitiveAtom } from "jotai";
 import { Scope } from "jotai/core/atom";
-import { useUpdateAtom } from "jotai/utils";
+import { useUpdateAtom, RESET } from "jotai/utils";
 import {
   doc,
   DocumentData,
   onSnapshot,
   FirestoreError,
   setDoc,
+  DocumentReference,
 } from "firebase/firestore";
 import { useErrorHandler } from "react-error-boundary";
 
 import { globalScope } from "@src/atoms/globalScope";
+import { UpdateFunction } from "@src/atoms/types";
 import { firebaseDbAtom } from "@src/sources/ProjectSourceFirebase";
 
 /** Options for {@link useFirestoreDocWithAtom} */
@@ -24,6 +26,8 @@ interface IUseFirestoreDocWithAtomOptions<T> {
   disableSuspense?: boolean;
   /** Optionally create the document if it doesn’t exist with the following data */
   createIfNonExistent?: T;
+  /** Set this atom’s value to a function that updates the document. Uses same scope as `dataScope`. */
+  updateDataAtom?: PrimitiveAtom<UpdateFunction<T> | null>;
 }
 
 /**
@@ -45,11 +49,20 @@ export function useFirestoreDocWithAtom<T = DocumentData>(
 ) {
   const [firebaseDb] = useAtom(firebaseDbAtom, globalScope);
   const setDataAtom = useUpdateAtom(dataAtom, dataScope);
+  const setUpdateDataAtom = useUpdateAtom(
+    options?.updateDataAtom || (dataAtom as any),
+    globalScope
+  );
   const handleError = useErrorHandler();
 
   // Destructure options so they can be used as useEffect dependencies
-  const { pathSegments, onError, disableSuspense, createIfNonExistent } =
-    options || {};
+  const {
+    pathSegments,
+    onError,
+    disableSuspense,
+    createIfNonExistent,
+    updateDataAtom,
+  } = options || {};
 
   useEffect(() => {
     if (!path || (Array.isArray(pathSegments) && pathSegments.some((x) => !x)))
@@ -63,8 +76,14 @@ export function useFirestoreDocWithAtom<T = DocumentData>(
       suspended = true;
     }
 
+    const ref = doc(
+      firebaseDb,
+      path,
+      ...((pathSegments as string[]) || [])
+    ) as DocumentReference<T>;
+
     const unsubscribe = onSnapshot(
-      doc(firebaseDb, path, ...((pathSegments as string[]) || [])),
+      ref,
       (doc) => {
         try {
           if (!doc.exists() && !!createIfNonExistent) {
@@ -86,8 +105,19 @@ export function useFirestoreDocWithAtom<T = DocumentData>(
       }
     );
 
+    // If `options?.updateDataAtom` was passed,
+    // set the atom’s value to a function that updates the document
+    if (updateDataAtom) {
+      setUpdateDataAtom(
+        () => (update: T) => setDoc(ref, update, { merge: true })
+      );
+    }
+
     return () => {
       unsubscribe();
+      // If `options?.updateDataAtom` was passed,
+      // reset the atom’s value to prevent writes
+      if (updateDataAtom) setUpdateDataAtom(RESET);
     };
   }, [
     firebaseDb,
@@ -98,6 +128,8 @@ export function useFirestoreDocWithAtom<T = DocumentData>(
     disableSuspense,
     createIfNonExistent,
     handleError,
+    updateDataAtom,
+    setUpdateDataAtom,
   ]);
 }
 
diff --git a/src/pages/JotaiTest.tsx b/src/pages/JotaiTest.tsx
index e9e25e27..f94cce52 100644
--- a/src/pages/JotaiTest.tsx
+++ b/src/pages/JotaiTest.tsx
@@ -12,6 +12,7 @@ import {
 } from "@src/atoms/globalScope";
 import { firebaseAuthAtom } from "@src/sources/ProjectSourceFirebase";
 import { Button } from "@mui/material";
+import MultiSelect from "@rowy/multiselect";
 import { useSnackbar } from "notistack";
 import { useFirestoreDocWithAtom } from "hooks/useFirestoreDocWithAtom";
 
@@ -77,6 +78,13 @@ function JotaiTest() {
         Sign out
       </Button>
 
+      <MultiSelect
+        multiple={false}
+        onChange={console.log}
+        value="2"
+        options={new Array(10).fill(undefined).map((_, i) => i.toString())}
+      />
+
       <Button onClick={() => getIdTokenResult(currentUser!).then(console.log)}>
         getIdTokenResult
       </Button>
diff --git a/src/pages/Settings/ProjectSettings.tsx b/src/pages/Settings/ProjectSettings.tsx
index aed6424a..77fa5921 100644
--- a/src/pages/Settings/ProjectSettings.tsx
+++ b/src/pages/Settings/ProjectSettings.tsx
@@ -14,7 +14,9 @@ import Customization from "@src/components/Settings/ProjectSettings/Customizatio
 import {
   globalScope,
   projectSettingsAtom,
+  updateProjectSettingsAtom,
   publicSettingsAtom,
+  updatePublicSettingsAtom,
 } from "@src/atoms/globalScope";
 
 export interface IProjectSettingsChildProps {
@@ -30,20 +32,21 @@ export default function ProjectSettingsPage() {
 
   const { enqueueSnackbar } = useSnackbar();
 
-  const updateProjectSettings = useDebouncedCallback(
-    (data: Record<string, any>) => {
-      // TODO:
-      // db
-      //   .doc(path)
-      //   .update(data)
-      //   .then(() =>
-
-      enqueueSnackbar("Saved", { variant: "success" });
-
-      // )
-    },
-    1000
+  const [_updateProjectSettingsDoc] = useAtom(
+    updateProjectSettingsAtom,
+    globalScope
   );
+  const updateProjectSettings = useDebouncedCallback((data) => {
+    if (_updateProjectSettingsDoc) {
+      _updateProjectSettingsDoc(data).then(() =>
+        enqueueSnackbar("Saved", { variant: "success" })
+      );
+    } else {
+      enqueueSnackbar("Could not update project settings", {
+        variant: "error",
+      });
+    }
+  }, 1000);
   // When the component is to be unmounted, force update settings
   useEffect(
     () => () => {
@@ -52,17 +55,21 @@ export default function ProjectSettingsPage() {
     [updateProjectSettings]
   );
 
+  const [_updatePublicSettingsDoc] = useAtom(
+    updatePublicSettingsAtom,
+    globalScope
+  );
   const updatePublicSettings = useDebouncedCallback(
     (data: Record<string, any>) => {
-      // TODO:
-      // db
-      //   .doc(path)
-      //   .update(data)
-      //   .then(() =>
-
-      enqueueSnackbar("Saved", { variant: "success" });
-
-      // )
+      if (_updatePublicSettingsDoc) {
+        _updatePublicSettingsDoc(data).then(() =>
+          enqueueSnackbar("Saved", { variant: "success" })
+        );
+      } else {
+        enqueueSnackbar("Could not update public settings", {
+          variant: "error",
+        });
+      }
     },
     1000
   );
diff --git a/src/pages/Settings/UserSettings.tsx b/src/pages/Settings/UserSettings.tsx
index ac65bb75..75c1e3e3 100644
--- a/src/pages/Settings/UserSettings.tsx
+++ b/src/pages/Settings/UserSettings.tsx
@@ -15,6 +15,7 @@ import {
   globalScope,
   currentUserAtom,
   userSettingsAtom,
+  updateUserSettingsAtom,
 } from "@src/atoms/globalScope";
 
 export interface IUserSettingsChildProps {
@@ -27,16 +28,17 @@ export default function UserSettingsPage() {
   const [userSettings] = useAtom(userSettingsAtom, globalScope);
   const { enqueueSnackbar } = useSnackbar();
 
-  const updateSettings = useDebouncedCallback((data: Record<string, any>) => {
-    // TODO:
-    // db
-    //   .doc(path)
-    //   .update(data)
-    //   .then(() =>
-
-    enqueueSnackbar("Saved", { variant: "success" });
-
-    // )
+  const [_updateUserSettings] = useAtom(updateUserSettingsAtom, globalScope);
+  const updateSettings = useDebouncedCallback((data) => {
+    if (_updateUserSettings) {
+      _updateUserSettings(data).then(() =>
+        enqueueSnackbar("Saved", { variant: "success" })
+      );
+    } else {
+      enqueueSnackbar("Could not update project settings", {
+        variant: "error",
+      });
+    }
   }, 1000);
   // When the component is to be unmounted, force update settings
   useEffect(
diff --git a/src/sources/ProjectSourceFirebase.tsx b/src/sources/ProjectSourceFirebase.tsx
index 48f2edea..5f15f332 100644
--- a/src/sources/ProjectSourceFirebase.tsx
+++ b/src/sources/ProjectSourceFirebase.tsx
@@ -15,10 +15,13 @@ import {
   globalScope,
   projectIdAtom,
   projectSettingsAtom,
+  updateProjectSettingsAtom,
   publicSettingsAtom,
+  updatePublicSettingsAtom,
   currentUserAtom,
   userRolesAtom,
   userSettingsAtom,
+  updateUserSettingsAtom,
   UserSettings,
 } from "@src/atoms/globalScope";
 import { SETTINGS, PUBLIC_SETTINGS, USERS } from "@src/config/dbPaths";
@@ -120,17 +123,20 @@ export default function ProjectSourceFirebase() {
   }, [firebaseAuth, setCurrentUser, setUserRoles]);
 
   // Store public settings in atom
-  useFirestoreDocWithAtom(publicSettingsAtom, globalScope, PUBLIC_SETTINGS);
+  useFirestoreDocWithAtom(publicSettingsAtom, globalScope, PUBLIC_SETTINGS, {
+    updateDataAtom: updatePublicSettingsAtom,
+  });
 
   // Store public settings in atom when a user is signed in
   useFirestoreDocWithAtom(
     projectSettingsAtom,
     globalScope,
-    currentUser ? SETTINGS : undefined
+    currentUser ? SETTINGS : undefined,
+    { updateDataAtom: updateProjectSettingsAtom }
   );
 
   // Store user settings in atom when a user is signed in
-  useFirestoreDocWithAtom<UserSettings>(userSettingsAtom, globalScope, USERS, {
+  useFirestoreDocWithAtom(userSettingsAtom, globalScope, USERS, {
     pathSegments: [currentUser?.uid],
     createIfNonExistent: currentUser
       ? {
@@ -142,6 +148,7 @@ export default function ProjectSourceFirebase() {
           },
         }
       : undefined,
+    updateDataAtom: updateUserSettingsAtom,
   });
 
   return null;
diff --git a/src/theme/ThemeProvider.tsx b/src/theme/RowyThemeProvider.tsx
similarity index 87%
rename from src/theme/ThemeProvider.tsx
rename to src/theme/RowyThemeProvider.tsx
index c9bb224c..c308694a 100644
--- a/src/theme/ThemeProvider.tsx
+++ b/src/theme/RowyThemeProvider.tsx
@@ -2,11 +2,7 @@ import { useEffect } from "react";
 import { useAtom } from "jotai";
 import { Helmet } from "react-helmet-async";
 
-import {
-  useMediaQuery,
-  ThemeProvider as MuiThemeProvider,
-  CssBaseline,
-} from "@mui/material";
+import { useMediaQuery, ThemeProvider, CssBaseline } from "@mui/material";
 import Favicon from "@src/assets/Favicon";
 
 import { globalScope } from "@src/atoms/globalScope";
@@ -20,7 +16,7 @@ import {
  * Injects the MUI theme with customizations from project and user settings.
  * Also adds dark mode support.
  */
-export default function ThemeProvider({
+export default function RowyThemeProvider({
   children,
 }: React.PropsWithChildren<{}>) {
   const [theme, setTheme] = useAtom(themeAtom, globalScope);
@@ -55,11 +51,11 @@ export default function ThemeProvider({
         </Helmet>
       )}
 
-      <MuiThemeProvider theme={customizedThemes[theme]}>
+      <ThemeProvider theme={customizedThemes[theme]}>
         <Favicon />
         <CssBaseline />
         {children}
-      </MuiThemeProvider>
+      </ThemeProvider>
     </>
   );
 }