diff --git a/packages/gatekeeper-context/app/main.tsx b/packages/gatekeeper-context/app/main.tsx
index 6393c090..5e902c3e 100644
--- a/packages/gatekeeper-context/app/main.tsx
+++ b/packages/gatekeeper-context/app/main.tsx
@@ -8,18 +8,22 @@ import type { RpcStub } from 'capnweb'
 import type { ContextApi } from '../src/context-types'
 import ContextLibraryPage from './ContextLibraryPage'
 import { ContextApiProvider, PresentationProvider, type PresentAck } from './bridge'
-import { applyThemeMode, type ResolvedThemeMode } from './theme'
+import { applyAccentVariables, applyThemeMode, type ResolvedThemeMode } from './theme'
 import './styles.css'
 import ErrorBoundary from './ErrorBoundary'
 import { installErrorReporting, reportIssue } from './error-reporting'
 
 installErrorReporting()
 
-// The only capability the iframe exposes back to the host: a receiver for theme-mode pushes.
+// The only capability the iframe exposes back to the host: a receiver for theme pushes.
 class AppIframe extends RpcTarget {
   setThemeMode(mode: ResolvedThemeMode): void {
     applyThemeMode(mode)
   }
+
+  setAccentVariables(variables: Record<string, string> | null): void {
+    applyAccentVariables(variables)
+  }
 }
 
 interface HostCapability extends RpcTarget {
@@ -28,6 +32,7 @@ interface HostCapability extends RpcTarget {
   setPresenting(active: boolean): Promise<PresentAck>
   // Returns the current resolved theme mode and calls back on `receiver` whenever it changes.
   subscribeTheme(receiver: AppIframe): Promise<ResolvedThemeMode>
+  subscribeAccent(receiver: AppIframe): Promise<Record<string, string> | null>
 }
 
 function main() {
@@ -42,6 +47,7 @@ function main() {
   const host = newMessagePortRpcSession<HostCapability>(port1, iframe)
   // The initial mode comes back from the call; later changes arrive via iframe.setThemeMode().
   host.subscribeTheme(iframe).then(applyThemeMode).catch(() => {})
+  host.subscribeAccent(iframe).then(applyAccentVariables).catch(() => {})
 
   createRoot(root, {
     onUncaughtError: (error) => reportIssue('context.react-root', error, {
diff --git a/packages/gatekeeper-context/app/theme.ts b/packages/gatekeeper-context/app/theme.ts
index e66c5269..4f111168 100644
--- a/packages/gatekeeper-context/app/theme.ts
+++ b/packages/gatekeeper-context/app/theme.ts
@@ -12,6 +12,8 @@
 // The two concrete modes the host resolves `light`/`dark`/`system` down to before pushing it here.
 export type ResolvedThemeMode = "light" | "dark";
 
+const appliedAccentVariables = new Set<string>();
+
 // Seed from the pre-paint `data-mode` the bootstrap script in index.html set from the OS preference,
 // so imperative widgets that read getThemeMode() before the host's RPC arrives start correct.
 let current: ResolvedThemeMode =
@@ -32,6 +34,16 @@ export function applyThemeMode(mode: ResolvedThemeMode): void {
   for (const listener of listeners) listener(mode);
 }
 
+export function applyAccentVariables(values: Record<string, string> | null): void {
+  const root = document.documentElement;
+  for (const variable of appliedAccentVariables) root.style.removeProperty(variable);
+  appliedAccentVariables.clear();
+  for (const [variable, value] of Object.entries(values ?? {})) {
+    root.style.setProperty(variable, value);
+    appliedAccentVariables.add(variable);
+  }
+}
+
 // Subscribe to mode changes. Returns an unsubscribe function.
 export function subscribeThemeMode(
   listener: (mode: ResolvedThemeMode) => void,
diff --git a/packages/gatekeeper-scheduler/app/main.tsx b/packages/gatekeeper-scheduler/app/main.tsx
index 48614ae8..c0568cce 100644
--- a/packages/gatekeeper-scheduler/app/main.tsx
+++ b/packages/gatekeeper-scheduler/app/main.tsx
@@ -3,7 +3,7 @@ import { RpcTarget, newMessagePortRpcSession, type RpcStub } from "capnweb";
 import SchedulerPage, { type ScheduleManagementClient } from "./SchedulerPage";
 import ErrorBoundary from "./ErrorBoundary";
 import { installErrorReporting, reportIssue } from "./error-reporting";
-import { applyThemeMode, type ResolvedThemeMode } from "./theme";
+import { applyAccentVariables, applyThemeMode, type ResolvedThemeMode } from "./theme";
 import "./styles.css";
 
 installErrorReporting();
@@ -12,11 +12,16 @@ class AppIframe extends RpcTarget {
   setThemeMode(mode: ResolvedThemeMode): void {
     applyThemeMode(mode);
   }
+
+  setAccentVariables(variables: Record<string, string> | null): void {
+    applyAccentVariables(variables);
+  }
 }
 
 interface HostCapability extends RpcTarget {
   readonly ui: RpcStub<ScheduleManagementClient>;
   subscribeTheme(receiver: AppIframe): Promise<ResolvedThemeMode>;
+  subscribeAccent(receiver: AppIframe): Promise<Record<string, string> | null>;
   openWorkspace(workspaceId: string, gadgetId?: number): Promise<void>;
   resolveWorkspaceTitles(ids: string[]): Promise<(string | null)[]>;
   openPrompt(prompt: string): Promise<void>;
@@ -34,6 +39,7 @@ function main() {
     .subscribeTheme(iframe)
     .then(applyThemeMode)
     .catch(() => {});
+  host.subscribeAccent(iframe).then(applyAccentVariables).catch(() => {});
 
   createRoot(element, {
     onUncaughtError: (error) =>
diff --git a/packages/gatekeeper-scheduler/app/theme.ts b/packages/gatekeeper-scheduler/app/theme.ts
index 81f9609b..57cf22c7 100644
--- a/packages/gatekeeper-scheduler/app/theme.ts
+++ b/packages/gatekeeper-scheduler/app/theme.ts
@@ -1,6 +1,18 @@
 export type ResolvedThemeMode = "light" | "dark";
 
+const appliedAccentVariables = new Set<string>();
+
 export function applyThemeMode(mode: ResolvedThemeMode): void {
   document.documentElement.dataset.mode = mode;
   document.documentElement.style.colorScheme = mode;
 }
+
+export function applyAccentVariables(values: Record<string, string> | null): void {
+  const root = document.documentElement;
+  for (const variable of appliedAccentVariables) root.style.removeProperty(variable);
+  appliedAccentVariables.clear();
+  for (const [variable, value] of Object.entries(values ?? {})) {
+    root.style.setProperty(variable, value);
+    appliedAccentVariables.add(variable);
+  }
+}
diff --git a/packages/workshop-frontend/src/SandboxedGatekeeperApp.tsx b/packages/workshop-frontend/src/SandboxedGatekeeperApp.tsx
index 6344fbe6..8b50f566 100644
--- a/packages/workshop-frontend/src/SandboxedGatekeeperApp.tsx
+++ b/packages/workshop-frontend/src/SandboxedGatekeeperApp.tsx
@@ -3,9 +3,11 @@ import { flushSync } from 'react-dom'
 import { RpcStub, RpcTarget, newMessagePortRpcSession } from 'capnweb'
 import { useNavigate } from '@tanstack/react-router'
 import type { GatekeeperUiFrame } from '@gadgets/workshop-shared/gatekeeper'
+import { isHexColor } from '@gadgets/workshop-shared/api'
 import { createRateLimitedCapability } from './rateLimitedCapability'
 import { useTheme } from './ThemeContext'
-import type { ResolvedThemeMode } from './theme'
+import { accentVars, type ResolvedThemeMode } from './theme'
+import { useServerConfig } from './ServerConfigContext'
 import { forwardTrustedFrameError } from './errorReporting'
 import { useAuthenticatedApi } from './AuthContext'
 import {
@@ -19,6 +21,14 @@ interface ThemeReceiver extends RpcTarget {
   setThemeMode(mode: ResolvedThemeMode): void
 }
 
+interface AccentReceiver extends RpcTarget {
+  setAccentVariables(variables: Record<string, string> | null): void
+}
+
+function accentVariablesFor(color: string | null): Record<string, string> | null {
+  return color && isHexColor(color) ? accentVars(color) : null
+}
+
 // The content-pane rect, in viewport coordinates, that the app pins its page to while the iframe
 // is full-viewport.
 type OverlayRect = { left: number; top: number; width: number; height: number }
@@ -84,7 +94,9 @@ class GatekeeperAppHostImpl extends RpcTarget {
   readonly #resolveWorkspaceTitles: ResolveWorkspaceTitles
   #presenting = false
   #themeMode: ResolvedThemeMode
+  #accentVariables: Record<string, string> | null
   #themeReceiver: RpcStub<ThemeReceiver> | null = null
+  #accentReceiver: RpcStub<AccentReceiver> | null = null
   // Presentation changes are coalesced to a single apply per animation frame (see #applyPending).
   #pendingActive: boolean | null = null
   #pendingResolvers: ((ack: PresentAck) => void)[] = []
@@ -94,12 +106,14 @@ class GatekeeperAppHostImpl extends RpcTarget {
     capability: any,
     present: PresentController,
     themeMode: ResolvedThemeMode,
+    accentVariables: Record<string, string> | null,
     openTarget: OpenTarget,
     openPrompt: OpenPrompt,
     resolveWorkspaceTitles: ResolveWorkspaceTitles,
   ) {
     super()
     this.#themeMode = themeMode
+    this.#accentVariables = accentVariables
     const { capability: ui, dispose } = createRateLimitedCapability(capability, {
       maxConcurrency: 8,
       maxCallsPerMinute: 600,
@@ -147,12 +161,24 @@ class GatekeeperAppHostImpl extends RpcTarget {
     return this.#themeMode
   }
 
+  subscribeAccent(receiver: RpcStub<AccentReceiver>): Record<string, string> | null {
+    this.#accentReceiver?.[Symbol.dispose]?.()
+    this.#accentReceiver = receiver.dup()
+    return this.#accentVariables
+  }
+
   #dropThemeReceiver(receiver: RpcStub<ThemeReceiver>) {
     if (this.#themeReceiver !== receiver) return
     receiver[Symbol.dispose]?.()
     this.#themeReceiver = null
   }
 
+  #dropAccentReceiver(receiver: RpcStub<AccentReceiver>) {
+    if (this.#accentReceiver !== receiver) return
+    receiver[Symbol.dispose]?.()
+    this.#accentReceiver = null
+  }
+
   // Push a new mode to a subscribed app; a no-op until (and unless) the app subscribes.
   updateTheme(mode: ResolvedThemeMode) {
     this.#themeMode = mode
@@ -166,6 +192,19 @@ class GatekeeperAppHostImpl extends RpcTarget {
     }
   }
 
+  updateAccentVariables(variables: Record<string, string> | null) {
+    this.#accentVariables = variables
+    const receiver = this.#accentReceiver
+    if (!receiver) return
+
+    try {
+      Promise.resolve(receiver.setAccentVariables(variables))
+        .catch(() => this.#dropAccentReceiver(receiver))
+    } catch {
+      this.#dropAccentReceiver(receiver)
+    }
+  }
+
   // Queue a presentation change; the latest requested state is applied on the next frame.
   setPresenting(active: boolean): Promise<PresentAck> {
     return new Promise((resolve) => {
@@ -194,6 +233,8 @@ class GatekeeperAppHostImpl extends RpcTarget {
     this.#disposeRateLimiter()
     this.#themeReceiver?.[Symbol.dispose]?.()
     this.#themeReceiver = null
+    this.#accentReceiver?.[Symbol.dispose]?.()
+    this.#accentReceiver = null
     if (this.#frameId !== null) {
       cancelAnimationFrame(this.#frameId)
       this.#frameId = null
@@ -224,13 +265,19 @@ export default function SandboxedGatekeeperApp({ frame, gatekeeperVendorId }: {
   const invalidatedRef = useRef(false)
   const [overlay, setOverlay] = useState<OverlayState>(null)
   const overlayRef = useRef<OverlayState>(null)
-  // Push the Workshop's resolved light/dark mode to the app whenever it changes.
+  // Push the Workshop's resolved light/dark mode and deployment accent into the sandboxed app.
   const { resolvedThemeMode } = useTheme()
+  const accentColor = useServerConfig()?.accentColor ?? null
   const themeModeRef = useRef(resolvedThemeMode)
+  const accentVariablesRef = useRef(accentVariablesFor(accentColor))
   themeModeRef.current = resolvedThemeMode
+  accentVariablesRef.current = accentVariablesFor(accentColor)
   useEffect(() => {
     hostRef.current?.updateTheme(resolvedThemeMode)
   }, [resolvedThemeMode])
+  useEffect(() => {
+    hostRef.current?.updateAccentVariables(accentVariablesFor(accentColor))
+  }, [accentColor])
 
   const setOverlayPhase = useCallback((next: OverlayState) => {
     if (overlayRef.current === next) return
@@ -313,6 +360,7 @@ export default function SandboxedGatekeeperApp({ frame, gatekeeperVendorId }: {
         capabilityRef.current,
         present,
         themeModeRef.current,
+        accentVariablesRef.current,
         openTarget,
         openPrompt,
         resolveWorkspaceTitles,
diff --git a/packages/workshop-frontend/src/theme.ts b/packages/workshop-frontend/src/theme.ts
index 10fe1de0..d38e9fc3 100644
--- a/packages/workshop-frontend/src/theme.ts
+++ b/packages/workshop-frontend/src/theme.ts
@@ -63,7 +63,7 @@ export function applyStoredThemeMode(): ResolvedThemeMode {
 
 // Variables derived from the seed, as (name -> value-template) pairs. `light-dark()` keeps custom
 // deployment accents mode-aware without needing to reapply them when the user toggles themes.
-function accentVars(seed: string): Record<string, string> {
+export function accentVars(seed: string): Record<string, string> {
   return {
     '--color-kumo-brand': `light-dark(${seed}, oklch(from ${seed} 0.45 c h))`,
     // Slightly darker for hover/pressed states.