diff --git a/src/services/ThemeService.js b/src/services/ThemeService.js
index 1b57d938..ca283a7f 100644
--- a/src/services/ThemeService.js
+++ b/src/services/ThemeService.js
@@ -1,5 +1,10 @@
+import UIAlert from "../UI/UIAlert.js";
 import { Service } from "../definitions.js";
 
+const PUTER_THEME_DATA_FILENAME = '~/.__puter_gui.json';
+
+const SAVE_COOLDOWN_TIME = 1000;
+
 export class ThemeService extends Service {
     async _init () {
         this.state = {
@@ -11,6 +16,46 @@ export class ThemeService extends Service {
         this.root = document.querySelector(':root');
         // this.ss = new CSSStyleSheet();
         // document.adoptedStyleSheets.push(this.ss);
+
+        this.save_cooldown_ = undefined;
+
+        let data = undefined;
+        try {
+            data = await puter.fs.read(PUTER_THEME_DATA_FILENAME);
+            if ( typeof data === 'object' ) {
+                data = await data.text();
+            }
+        } catch (e) {
+            if ( e.code !== 'subject_does_not_exist' ) {
+                // TODO: once we have an event log,
+                //       log this error to the event log
+                console.error(e);
+
+                // We don't show an alert becuase it's likely
+                // other things also aren't working.
+            }
+        }
+
+        if ( data ) try {
+            data = JSON.parse(data.toString());
+        } catch (e) {
+            data = undefined;
+            console.error(e);
+
+            UIAlert({
+                title: 'Error loading theme data',
+                message: `Could not parse "${PUTER_THEME_DATA_FILENAME}": ` +
+                    e.message,
+            });
+        }
+
+        if ( data && data.colors ) {
+            this.state = {
+                ...this.state,
+                ...data.colors,
+            };
+            this.reload_();
+        }
     }
 
     apply (values) {
@@ -19,6 +64,7 @@ export class ThemeService extends Service {
             ...values,
         };
         this.reload_();
+        this.save_();
     }
 
     get (key) { return this.state[key]; }
@@ -37,4 +83,20 @@ export class ThemeService extends Service {
         this.root.style.setProperty('--primary-lightness', s.lig + '%');
         this.root.style.setProperty('--primary-alpha', s.alpha);
     }
+
+    save_ () {
+        if ( this.save_cooldown_ ) {
+            clearTimeout(this.save_cooldown_);
+        }
+        this.save_cooldown_ = setTimeout(() => {
+            this.commit_save_();
+        }, SAVE_COOLDOWN_TIME);
+    }
+    commit_save_ () {
+        puter.fs.write(PUTER_THEME_DATA_FILENAME, JSON.stringify(
+            { colors: this.state },
+            undefined,
+            4,
+        ));
+    }
 }