--- a/browser/base/content/default-theme-icon.svg
+++ b/browser/base/content/default-theme-icon.svg
@@ -1,13 +1,11 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- This Source Code Form is subject to the terms of the Mozilla Public
-   - License, v. 2.0. If a copy of the MPL was not distributed with this
-   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32">
-    <rect fill="#fff" x="1" y="1" width="30" height="30" rx="2" ry="2"/>
-    <path fill="#e3e3e3" d="M3 1h26a2 2 0 0 1 2 2v18H1V3a2 2 0 0 1 2-2z"/>
-    <rect stroke="gray" fill="#fff" x="10.5" y="5.5" width="18" height="11" rx="1" ry="1"/>
-    <circle fill="#fcfcfc" stroke="gray" stroke-width="1.2px" cx="11" cy="11" r="7.5"/>
-    <path fill="#595959" d="M14 10h-3.6l1.3-1.3a1 1 0 0 0-1.4-1.4l-3 3a1 1 0 0 0 0 1.4l3 3a1 1 0 0 0 1.4-1.4L10.4 12H14a1 1 0 0 0 0-2z"/>
-    <path fill="none" stroke="#999" d="M1.5 20.5h29"/>
-    <rect fill="none" stroke="#999" stroke-width="2" x="1" y="1" width="30" height="30" rx="2" ry="2"/>
-</svg>
+<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0 0 32 32">
+  <path fill="#202340" d="M2 2h14v13H2z"/>
+  <path fill="#f9f9fa" d="M16 2v13H2v15h28V2H16z"/>
+  <rect x="1" y="1" width="30" height="30" rx="2" ry="2" fill="none" stroke="#08091a" stroke-opacity=".35" stroke-width="2"/>
+  <circle cx="9.5" cy="22.5" r="6" fill="#fff" stroke="#adadb3"/>
+  <path d="M12.5 22H7.707l2.146-2.146a.5.5 0 0 0-.707-.707l-3 3a.5.5 0 0 0 0 .708l3 3a.5.5 0 1 0 .707-.707L7.707 23H12.5a.5.5 0 0 0 0-1z" fill="#0c0c0d" fill-opacity=".8"/>
+  <path d="M20.5 20h4a.5.5 0 0 0 0-1h-4a.5.5 0 0 0 0 1zm4 2h-4a.5.5 0 0 0 0 1h4a.5.5 0 0 0 0-1zm0 3h-4a.5.5 0 0 0 0 1h4a.5.5 0 0 0 0-1z" fill="#0c0c0d" fill-opacity=".8"/>
+  <path fill="#0a84ff" d="M16 2h14v1H16z"/>
+  <path d="M26.354 8.646l-3.5-3.5a.5.5 0 0 0-.707 0l-3.5 3.5a.5.5 0 0 0 .707.707L20 8.707V11.5a.5.5 0 0 0 .5.5h4a.5.5 0 0 0 .5-.5V8.707l.646.646a.5.5 0 1 0 .707-.707zM24 11h-1V9h-1v2h-1V7.707l1.5-1.5 1.5 1.5z" fill="#0c0c0d" fill-opacity=".8"/>
+  <path fill="#08091a" d="M15 2v12H2v1h14V2h-1z"/>
+</svg>
\ No newline at end of file

rename from browser/base/content/defaultthemes/compactdark.icon.svg
rename to browser/base/content/defaultthemes/dark.icon.svg
--- a/browser/base/content/defaultthemes/compactdark.icon.svg
+++ b/browser/base/content/defaultthemes/dark.icon.svg
@@ -1,16 +1,11 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!-- This Source Code Form is subject to the terms of the Mozilla Public
-   - License, v. 2.0. If a copy of the MPL was not distributed with this
-   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32">
-    <rect fill="#727780" x="1" y="1" width="30" height="30" rx="2" ry="2"/>
-    <path fill="#393f4c" d="M3 1h26a2 2 0 0 1 2 2v14H1V3a2 2 0 0 1 2-2z"/>
-    <rect fill="#171b1f" x="3.5" y="3.5" width="25" height="11" rx="1" ry="1"/>
-    <path fill="#252c33" d="M4.5 3.5h12v11h-12a1 1 0 0 1-1-1v-9a1 1 0 0 1 1-1z"/>
-    <rect stroke="#1d2328" fill="none" stroke-width="2" x="1" y="1" width="30" height="30" rx="2" ry="2"/>
-    <path class="icon-line-2px" d="M10 6L7 9l3 3M7.5 9H13"/>
-    <path stroke="#1d2328" d="M1.5 16.5h29"/>
-    <path class="separator-toolbar-items" d="M16.5 3.5v11"/>
-    <rect fill="none" stroke="#171b1f" x="3.5" y="3.5" width="25" height="11" rx="1" ry="1"/>
-    <path fill="#f0f1f2" d="M13 8H9.4l1.3-1.3a1 1 0 0 0-1.4-1.4l-3 3a1 1 0 0 0 0 1.4l3 3a1 1 0 0 0 1.4-1.4L9.4 10H13a1 1 0 0 0 0-2z"/>
-</svg>
+<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0 0 32 32">
+  <path fill="#0c0c0d" d="M2 2h14v13H2z"/>
+  <path fill="#323234" d="M16 2v13H2v15h28V2H16z"/>
+  <rect x="1" y="1" width="30" height="30" rx="2" ry="2" fill="none" stroke="#08091a" stroke-opacity=".35" stroke-width="2"/>
+  <circle cx="9.5" cy="22.5" r="6" fill="#474749" stroke="#08091a"/>
+  <path d="M12.5 22H7.707l2.146-2.146a.5.5 0 0 0-.707-.707l-3 3a.5.5 0 0 0 0 .708l3 3a.5.5 0 1 0 .707-.707L7.707 23H12.5a.5.5 0 0 0 0-1z" fill="#f9f9fa" fill-opacity=".8"/>
+  <path d="M20.5 20h4a.5.5 0 0 0 0-1h-4a.5.5 0 0 0 0 1zm4 2h-4a.5.5 0 0 0 0 1h4a.5.5 0 0 0 0-1zm0 3h-4a.5.5 0 0 0 0 1h4a.5.5 0 0 0 0-1z" fill="#f9f9fa" fill-opacity=".8"/>
+  <path fill="#0a84ff" d="M16 2h14v1H16z"/>
+  <path d="M26.354 8.646l-3.5-3.5a.5.5 0 0 0-.707 0l-3.5 3.5a.5.5 0 0 0 .707.707L20 8.707V11.5a.5.5 0 0 0 .5.5h4a.5.5 0 0 0 .5-.5V8.707l.646.646a.5.5 0 1 0 .707-.707zM24 11h-1V9h-1v2h-1V7.707l1.5-1.5 1.5 1.5z" fill="#f9f9fa" fill-opacity=".8"/>
+  <path fill="#08091a" d="M15 2v12H2v1h14V2h-1z"/>
+</svg>
\ No newline at end of file

rename from browser/base/content/defaultthemes/compactlight.icon.svg
rename to browser/base/content/defaultthemes/light.icon.svg
--- a/browser/base/content/defaultthemes/compactlight.icon.svg
+++ b/browser/base/content/defaultthemes/light.icon.svg
@@ -1,15 +1,11 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!-- This Source Code Form is subject to the terms of the Mozilla Public
-   - License, v. 2.0. If a copy of the MPL was not distributed with this
-   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32">
-    <rect fill="#fff" x="1" y="1" width="30" height="30" rx="2" ry="2"/>
-    <path fill="#e3e3e3" d="M3 1h26a2 2 0 0 1 2 2v14H1V3a2 2 0 0 1 2-2z"/>
-    <rect fill="#fff" x="3.5" y="3.5" width="25" height="11" rx="1" ry="1"/>
-    <path fill="#fcfcfc" d="M4.5 3.5h12v11h-12a1 1 0 0 1-1-1v-9a1 1 0 0 1 1-1z"/>
-    <rect fill="none" stroke="#999" stroke-width="2" x="1" y="1" width="30" height="30" rx="2" ry="2"/>
-    <path stroke="#999" d="M1.5 16.5h29"/>
-    <path stroke="#b3b3b3" d="M16.5 3.5v11"/>
-    <rect fill="none" stroke="#b3b3b3" x="3.5" y="3.5" width="25" height="11" rx="1" ry="1"/>
-    <path fill="#595959" d="M13 8H9.4l1.3-1.3a1 1 0 0 0-1.4-1.4l-3 3a1 1 0 0 0 0 1.4l3 3a1 1 0 0 0 1.4-1.4L9.4 10H13a1 1 0 0 0 0-2z"/>
-</svg>
+<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0 0 32 32">
+  <path fill="#e1e1e5" d="M2 2h14v13H2z"/>
+  <path fill="#f9f9fa" d="M16 2v13H2v15h28V2H16z"/>
+  <rect x="1" y="1" width="30" height="30" rx="2" ry="2" fill="none" stroke="#08091a" stroke-opacity=".35" stroke-width="2"/>
+  <circle cx="9.5" cy="22.5" r="6" fill="#fff" stroke="#adadb3"/>
+  <path d="M12.5 22H7.707l2.146-2.146a.5.5 0 0 0-.707-.707l-3 3a.5.5 0 0 0 0 .708l3 3a.5.5 0 1 0 .707-.707L7.707 23H12.5a.5.5 0 0 0 0-1z" fill="#0c0c0d" fill-opacity=".8"/>
+  <path d="M20.5 20h4a.5.5 0 0 0 0-1h-4a.5.5 0 0 0 0 1zm4 2h-4a.5.5 0 0 0 0 1h4a.5.5 0 0 0 0-1zm0 3h-4a.5.5 0 0 0 0 1h4a.5.5 0 0 0 0-1z" fill="#0c0c0d" fill-opacity=".8"/>
+  <path fill="#0a84ff" d="M16 2h14v1H16z"/>
+  <path d="M26.354 8.646l-3.5-3.5a.5.5 0 0 0-.707 0l-3.5 3.5a.5.5 0 0 0 .707.707L20 8.707V11.5a.5.5 0 0 0 .5.5h4a.5.5 0 0 0 .5-.5V8.707l.646.646a.5.5 0 1 0 .707-.707zM24 11h-1V9h-1v2h-1V7.707l1.5-1.5 1.5 1.5z" fill="#0c0c0d" fill-opacity=".8"/>
+  <path fill="#08091a" fill-opacity=".25" d="M15 2v12H2v1h14V2h-1z"/>
+</svg>
\ No newline at end of file

--- a/browser/base/content/test/general/browser_compacttheme.js
+++ b/browser/base/content/test/general/browser_compacttheme.js
@@ -48,17 +48,17 @@ add_task(async function startTests() {
   ok(!CompactTheme.isStyleSheetEnabled, "There is no compact style sheet when no lw theme is applied.");
 });
 
 function dummyLightweightTheme(id) {
   return {
     id,
     name: id,
     headerURL: "resource:///chrome/browser/content/browser/defaultthemes/compact.header.png",
-    iconURL: "resource:///chrome/browser/content/browser/defaultthemes/compactlight.icon.svg",
+    iconURL: "resource:///chrome/browser/content/browser/defaultthemes/light.icon.svg",
     textcolor: "red",
     accentcolor: "blue"
   };
 }
 
 add_task(async function testLightweightThemePreview() {
   if (SKIP_TEST) {
     ok(true, "No need to run this test since themes aren't installed");

--- a/browser/base/jar.mn
+++ b/browser/base/jar.mn
@@ -105,18 +105,18 @@ browser.jar:
         content/browser/defaultthemes/3.preview.png   (content/defaultthemes/3.preview.png)
         content/browser/defaultthemes/4.header.png    (content/defaultthemes/4.header.png)
         content/browser/defaultthemes/4.icon.png      (content/defaultthemes/4.icon.png)
         content/browser/defaultthemes/4.preview.png   (content/defaultthemes/4.preview.png)
         content/browser/defaultthemes/5.header.png    (content/defaultthemes/5.header.png)
         content/browser/defaultthemes/5.icon.jpg      (content/defaultthemes/5.icon.jpg)
         content/browser/defaultthemes/5.preview.jpg   (content/defaultthemes/5.preview.jpg)
         content/browser/defaultthemes/compact.header.png    (content/defaultthemes/compact.header.png)
-        content/browser/defaultthemes/compactdark.icon.svg  (content/defaultthemes/compactdark.icon.svg)
-        content/browser/defaultthemes/compactlight.icon.svg (content/defaultthemes/compactlight.icon.svg)
+        content/browser/defaultthemes/dark.icon.svg  (content/defaultthemes/dark.icon.svg)
+        content/browser/defaultthemes/light.icon.svg (content/defaultthemes/light.icon.svg)
         content/browser/newtab/newTab.xhtml           (content/newtab/newTab.xhtml)
 *       content/browser/newtab/newTab.js              (content/newtab/newTab.js)
         content/browser/newtab/newTab.css             (content/newtab/newTab.css)
         content/browser/newtab/alternativeDefaultSites.json   (content/newtab/alternativeDefaultSites.json)
 *       content/browser/pageinfo/pageInfo.xul         (content/pageinfo/pageInfo.xul)
         content/browser/pageinfo/pageInfo.js          (content/pageinfo/pageInfo.js)
         content/browser/pageinfo/pageInfo.css         (content/pageinfo/pageInfo.css)
         content/browser/pageinfo/pageInfo.xml         (content/pageinfo/pageInfo.xml)

--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -608,27 +608,27 @@ BrowserGlue.prototype = {
     if (AppConstants.INSTALL_COMPACT_THEMES) {
       let vendorShortName = gBrandBundle.GetStringFromName("vendorShortName");
 
       LightweightThemeManager.addBuiltInTheme({
         id: "firefox-compact-light@mozilla.org",
         name: gBrowserBundle.GetStringFromName("lightTheme.name"),
         description: gBrowserBundle.GetStringFromName("lightTheme.description"),
         headerURL: "resource:///chrome/browser/content/browser/defaultthemes/compact.header.png",
-        iconURL: "resource:///chrome/browser/content/browser/defaultthemes/compactlight.icon.svg",
+        iconURL: "resource:///chrome/browser/content/browser/defaultthemes/light.icon.svg",
         textcolor: "black",
         accentcolor: "white",
         author: vendorShortName,
       });
       LightweightThemeManager.addBuiltInTheme({
         id: "firefox-compact-dark@mozilla.org",
         name: gBrowserBundle.GetStringFromName("darkTheme.name"),
         description: gBrowserBundle.GetStringFromName("darkTheme.description"),
         headerURL: "resource:///chrome/browser/content/browser/defaultthemes/compact.header.png",
-        iconURL: "resource:///chrome/browser/content/browser/defaultthemes/compactdark.icon.svg",
+        iconURL: "resource:///chrome/browser/content/browser/defaultthemes/dark.icon.svg",
         textcolor: "white",
         accentcolor: "black",
         author: vendorShortName,
       });
     }
 
     Services.obs.notifyObservers(null, "browser-ui-startup-complete");
   },