diff --git a/package.json b/package.json
index 85836a1df..5ce083c10 100644
--- a/package.json
+++ b/package.json
@@ -106,6 +106,10 @@
     "prepare": "npm run panda",
     "panda": "panda codegen",
     "panda:watch": "panda codegen --watch",
+    "dev:link-ui": "rm -rf node_modules/@microbit/ui && ln -s ../../../ui/packages/ui node_modules/@microbit/ui && rm -rf styled-system && npm run panda",
+    "dev:link-ui-patterns": "rm -rf node_modules/@microbit/ui-patterns && ln -s ../../../ui/packages/ui-patterns node_modules/@microbit/ui-patterns && rm -rf styled-system && npm run panda",
+    "dev:link-theme": "npm --prefix ../python-editor-v3-microbit run build && mkdir -p node_modules/@microbit-foundation && rm -rf node_modules/@microbit-foundation/python-editor-v3-microbit && ln -s ../../../python-editor-v3-microbit node_modules/@microbit-foundation/python-editor-v3-microbit && rm -rf styled-system && npm run panda",
+    "dev:unlink-theme": "rm -rf node_modules/@microbit-foundation/python-editor-v3-microbit && rm -rf styled-system && npm run panda",
     "serve": "npx serve --no-clipboard -l 3000 -- build/",
     "prestart": "npm run panda",
     "start": "vite dev",
diff --git a/src/common/GenericDialog.tsx b/src/common/GenericDialog.tsx
index fc4310ceb..febea7a64 100644
--- a/src/common/GenericDialog.tsx
+++ b/src/common/GenericDialog.tsx
@@ -78,7 +78,7 @@ export const GenericDialogFooter = ({
           variant="link"
           size="lg"
           onPress={onCloseDontShowAgain}
-          css={{ color: "brand.500", mr: "auto" }}
+          css={{ color: "fg.link", mr: "auto" }}
         >
           <FormattedMessage id="dont-show-again" />
         </Button>
diff --git a/src/common/PostSaveDialog.tsx b/src/common/PostSaveDialog.tsx
index 53cdc2127..f2494438e 100644
--- a/src/common/PostSaveDialog.tsx
+++ b/src/common/PostSaveDialog.tsx
@@ -125,7 +125,7 @@ const PostSaveDialogBody = ({
           values={{
             link: (chunks: ReactNode) => (
               <Link
-                color="brand.500"
+                color="fg.link"
                 onClick={handleShowTransferHexHelp}
                 href=""
                 cursor="pointer"
diff --git a/src/deployment/default/panda-preset.test.ts b/src/deployment/default/panda-preset.test.ts
new file mode 100644
index 000000000..37bfeeb64
--- /dev/null
+++ b/src/deployment/default/panda-preset.test.ts
@@ -0,0 +1,62 @@
+/**
+ * (c) 2026, Micro:bit Educational Foundation and contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+import {
+  droppedConditionTokens,
+  unknownSemanticTokens,
+} from "@microbit/ui/preset-lint";
+import { createRequire } from "node:module";
+import { describe, expect, it } from "vitest";
+import { appPreset } from "./panda-preset";
+
+// Panda accepts an unknown `semanticTokens` key silently — the override
+// never applies and nothing fails, so a rename in @microbit/ui would leave
+// this app on the library's colours with a green typecheck. See the
+// CSS-variable contract in @microbit/ui's README.
+
+// This app's own semantic tokens, which the base preset does not define.
+const introduces = [
+  "colors.sidebarHeaderBg",
+  "colors.sidebarTablistBg",
+  "colors.sidebarTabSelectedText",
+  "colors.sidebarTabSelectedBg",
+];
+
+it("app preset overrides only semantic tokens @microbit/ui defines", () => {
+  expect(unknownSemanticTokens(appPreset, { introduces })).toEqual([]);
+});
+
+// A flat override of a { base, _onDark } token merges wholesale and
+// silently drops the dark-surface flip — the same failure, one door over.
+it("app preset keeps every condition the base preset's tokens carry", () => {
+  expect(droppedConditionTokens(appPreset)).toEqual([]);
+});
+
+// The private brand preset is optional — present only when linked
+// (`npm run dev:link-theme`) or installed in a brand build, exactly as
+// panda.config.ts treats it. Checked here rather than in its own repo so
+// that repo stays free of a dependency on this library, and because the
+// merge this guards against happens on this side.
+const require = createRequire(import.meta.url);
+let brandPreset: unknown;
+try {
+  brandPreset = (
+    require("@microbit-foundation/python-editor-v3-microbit/panda-preset") as {
+      default: unknown;
+    }
+  ).default;
+} catch {
+  brandPreset = undefined;
+}
+
+describe.skipIf(!brandPreset)("private brand preset", () => {
+  it("overrides only semantic tokens @microbit/ui defines", () => {
+    expect(unknownSemanticTokens(brandPreset, { introduces })).toEqual([]);
+  });
+
+  it("keeps every condition the base preset's tokens carry", () => {
+    expect(droppedConditionTokens(brandPreset)).toEqual([]);
+  });
+});
diff --git a/src/documentation/api/ApiDocumentation.tsx b/src/documentation/api/ApiDocumentation.tsx
index 32f0d10ea..feddadf13 100644
--- a/src/documentation/api/ApiDocumentation.tsx
+++ b/src/documentation/api/ApiDocumentation.tsx
@@ -105,7 +105,7 @@ const ActiveLevel = ({
               id="api-description"
               values={{
                 link: (chunks: ReactNode) => (
-                  <Link color="brand.500" onClick={handleReferenceLink} href="">
+                  <Link color="fg.link" onClick={handleReferenceLink} href="">
                     {chunks}
                   </Link>
                 ),
diff --git a/src/documentation/common/DocumentationContent.tsx b/src/documentation/common/DocumentationContent.tsx
index df5984499..573354231 100644
--- a/src/documentation/common/DocumentationContent.tsx
+++ b/src/documentation/common/DocumentationContent.tsx
@@ -73,7 +73,7 @@ const DocumentationApiLinkMark = (
   const [, setState] = useRouterState();
   return (
     <Link
-      color="brand.600"
+      color="fg.link"
       onClick={(e) => {
         e.preventDefault();
         setState({
@@ -93,7 +93,7 @@ const DocumentationInternalLinkMark = (
   const [state, setState] = useRouterState();
   return (
     <Link
-      color="brand.600"
+      color="fg.link"
       onClick={(e) => {
         e.preventDefault();
         setState(
@@ -118,7 +118,7 @@ const DocumentationExternalLinkMark = (
 ) => {
   return (
     <Link
-      color="brand.600"
+      color="fg.link"
       href={props.mark.href}
       target="_blank"
       rel="nofollow noopener"
diff --git a/src/documentation/ideas/IdeasDocumentation.tsx b/src/documentation/ideas/IdeasDocumentation.tsx
index 44a3045e0..97167b579 100644
--- a/src/documentation/ideas/IdeasDocumentation.tsx
+++ b/src/documentation/ideas/IdeasDocumentation.tsx
@@ -176,7 +176,7 @@ const ActiveLevel = ({
           values={{
             link: (chunks: ReactNode) => (
               <Link
-                color="brand.500"
+                color="fg.link"
                 href={microbitOrgMiciProjectsUrl(languageId)}
                 target="_blank"
                 rel="noopener"
diff --git a/src/editor/ModuleOverlay.tsx b/src/editor/ModuleOverlay.tsx
index 60e6036bd..c8b4146bc 100644
--- a/src/editor/ModuleOverlay.tsx
+++ b/src/editor/ModuleOverlay.tsx
@@ -97,7 +97,7 @@ const ModuleOverlay = ({ moduleData }: ModuleOverlayProps) => {
               link: (chunks: ReactNode) => (
                 <Button
                   variant="link"
-                  css={{ color: "brand.500" }}
+                  css={{ color: "fg.link" }}
                   onPress={handleShowSettings}
                 >
                   {chunks}
diff --git a/src/workbench/AboutDialog/AboutDialog.tsx b/src/workbench/AboutDialog/AboutDialog.tsx
index ee809147c..1f15f2e41 100644
--- a/src/workbench/AboutDialog/AboutDialog.tsx
+++ b/src/workbench/AboutDialog/AboutDialog.tsx
@@ -122,7 +122,7 @@ const AboutDialog = ({ isOpen, onClose, finalFocusRef }: AboutDialogProps) => {
                   <Link
                     rel="noopener noreferrer"
                     target="blank"
-                    color="brand.500"
+                    color="fg.link"
                     href="https://github.com/microbit-foundation/python-editor-v3/graphs/contributors"
                   >
                     {chunks}
@@ -213,7 +213,7 @@ const AboutDialog = ({ isOpen, onClose, finalFocusRef }: AboutDialogProps) => {
               values={{
                 link: (chunks: ReactNode) => (
                   <Link
-                    color="brand.500"
+                    color="fg.link"
                     href="https://micropython.org"
                     target="_blank"
                     rel="noopener"
@@ -276,7 +276,7 @@ const MicroPythonSection = () => {
             values={{
               linkV1: (chunks: ReactNode) => (
                 <Link
-                  color="brand.500"
+                  color="fg.link"
                   href="https://github.com/bbcmicrobit/micropython"
                   target="_blank"
                   rel="noopener"
@@ -286,7 +286,7 @@ const MicroPythonSection = () => {
               ),
               linkV2: (_: ReactNode) => (
                 <Link
-                  color="brand.500"
+                  color="fg.link"
                   href="https://github.com/microbit-foundation/micropython-microbit-v2"
                   target="_blank"
                   rel="noopener"
@@ -299,7 +299,7 @@ const MicroPythonSection = () => {
         </Text>
         <Text fontSize="md">
           <Link
-            color="brand.500"
+            color="fg.link"
             href="https://ntoll.org/article/story-micropython-on-microbit/"
             target="_blank"
             rel="noopener"
diff --git a/src/workbench/WelcomeDialog.tsx b/src/workbench/WelcomeDialog.tsx
index 6fd04966c..d03eda1e4 100644
--- a/src/workbench/WelcomeDialog.tsx
+++ b/src/workbench/WelcomeDialog.tsx
@@ -62,7 +62,7 @@ const WelcomeDialog = ({ youtubeId, isOpen, onClose }: WelcomeDialogProps) => {
               values={{
                 link: (chunks: ReactNode) => (
                   <Link
-                    color="brand.500"
+                    color="fg.link"
                     target="_blank"
                     rel="noreferrer"
                     href={guideLink}
diff --git a/src/workbench/connect-dialogs/ConnectDialog.tsx b/src/workbench/connect-dialogs/ConnectDialog.tsx
index e49439678..77cd5d770 100644
--- a/src/workbench/connect-dialogs/ConnectDialog.tsx
+++ b/src/workbench/connect-dialogs/ConnectDialog.tsx
@@ -102,7 +102,7 @@ const ConnectDialogFooter = ({
           variant="link"
           size="lg"
           onPress={onNextDontShowAgain}
-          css={{ color: "brand.500", mr: "auto" }}
+          css={{ color: "fg.link", mr: "auto" }}
         >
           <FormattedMessage id="dont-show-again" />
         </Button>
diff --git a/src/workbench/connect-dialogs/FirmwareDialog.tsx b/src/workbench/connect-dialogs/FirmwareDialog.tsx
index 17f501726..03208e61c 100644
--- a/src/workbench/connect-dialogs/FirmwareDialog.tsx
+++ b/src/workbench/connect-dialogs/FirmwareDialog.tsx
@@ -69,7 +69,7 @@ const FirmwareDialogBody = () => {
               values={{
                 link: (chunks: ReactNode) => (
                   <Link
-                    color="brand.500"
+                    color="fg.link"
                     display="inline-flex"
                     alignItems="center"
                     target="_blank"
@@ -86,7 +86,7 @@ const FirmwareDialogBody = () => {
         </VStack>
       </HStack>
       <Link
-        color="brand.500"
+        color="fg.link"
         display="inline-flex"
         alignItems="center"
         target="_blank"
diff --git a/src/workbench/connect-dialogs/NotFoundDialog.tsx b/src/workbench/connect-dialogs/NotFoundDialog.tsx
index c81d96141..56088e5c4 100644
--- a/src/workbench/connect-dialogs/NotFoundDialog.tsx
+++ b/src/workbench/connect-dialogs/NotFoundDialog.tsx
@@ -87,11 +87,7 @@ const NotFoundDialogBody = ({
                 id="not-found-checklist-one"
                 values={{
                   link: (chunks: ReactNode) => (
-                    <Link
-                      color="brand.500"
-                      onClick={handleReviewDevice}
-                      href=""
-                    >
+                    <Link color="fg.link" onClick={handleReviewDevice} href="">
                       {chunks}
                     </Link>
                   ),
@@ -109,7 +105,7 @@ const NotFoundDialogBody = ({
                 values={{
                   link: (chunks: ReactNode) => (
                     <Link
-                      color="brand.500"
+                      color="fg.link"
                       display="inline-flex"
                       alignItems="center"
                       target="_blank"
@@ -130,7 +126,7 @@ const NotFoundDialogBody = ({
             </Text>
           </VStack>
           <Link
-            color="brand.500"
+            color="fg.link"
             display="inline-flex"
             alignItems="center"
             target="_blank"