diff --git a/ui-opentui/src/boundary/renderer.ts b/ui-opentui/src/boundary/renderer.ts
index 1131fd12990..807e4ad02be 100644
--- a/ui-opentui/src/boundary/renderer.ts
+++ b/ui-opentui/src/boundary/renderer.ts
@@ -12,7 +12,6 @@
 import { createCliRenderer, type CliRenderer, type KeyEvent, type Selection } from '@opentui/core'
 import { Deferred, Effect } from 'effect'
 
-import { DEFAULT_THEME } from '../logic/theme.ts'
 import { RendererError } from './errors.ts'
 import { installFfiCoordSafety } from './ffiSafe.ts'
 import { getLog } from './log.ts'
@@ -67,10 +66,10 @@ export const acquireRenderer = Effect.fn('Renderer.acquire')(function* (options:
     Effect.tryPromise({
       try: () =>
         createCliRenderer({
-          // Root canvas (design pass): paint the dark room from the first frame
-          // — true black by default. Skin overrides land reactively via the
-          // header's theme effect (view/header.tsx setBackgroundColor).
-          backgroundColor: DEFAULT_THEME.color.bg,
+          // Root canvas: TRANSPARENT by default — the terminal's own background
+          // shows through (do not paint a "default dark" canvas; glitch hated
+          // it). A skin's explicit ui_bg lands reactively via the header's
+          // theme effect (view/header.tsx setBackgroundColor).
           // scrollbox clips growing output → no terminal-scrollback corruption (gotcha §8 #2).
           externalOutputMode: 'passthrough',
           targetFps: 60,
diff --git a/ui-opentui/src/logic/theme.ts b/ui-opentui/src/logic/theme.ts
index 8cd63a3c2dd..19ac4d28ee3 100644
--- a/ui-opentui/src/logic/theme.ts
+++ b/ui-opentui/src/logic/theme.ts
@@ -12,6 +12,12 @@
  *
  * Source of truth for the contract: ui-tui/src/theme.ts (+ GatewaySkin in
  * ui-tui/src/gatewayTypes.ts). Keep this port in sync if that contract changes.
+ *
+ * INTENTIONAL divergences from the Ink port (visual-hierarchy design pass):
+ *   - `muted` is a true NEUTRAL grey (not a darker gold) and no longer borrows
+ *     the skin's `banner_dim` (a banner-gold shade in the stock skin); skins
+ *     override it via the dedicated `ui_muted` key instead.
+ *   - a `bg` token paints the root canvas (true black/white; `ui_bg` override).
  */
 
 import { FALSE_RE, TRUE_RE } from './env.ts'
@@ -22,9 +28,10 @@ export interface ThemeColors {
   border: string
   text: string
   muted: string
-  /** Root canvas background (design pass: the view is a dark room — true black
-   *  by default; skins may override via `ui_bg`). CSS names are valid OpenTUI
-   *  ColorInput, so the defaults use `black`/`white`, not invented hexes. */
+  /** Root canvas background. DEFAULT IS `transparent` — the terminal's own
+   *  background shows through (glitch rejected a painted "default dark" canvas;
+   *  the dark room is the user's terminal, not ours). Skins may opt into a
+   *  painted canvas via `ui_bg`. */
   bg: string
   completionBg: string
   completionCurrentBg: string
@@ -262,7 +269,7 @@ export const DARK_THEME: Theme = {
     // step, CSS `gray` — no invented hexes. Grey = everything that merely
     // happened; gold stays earned.
     muted: '#808080',
-    bg: 'black',
+    bg: 'transparent',
     completionBg: '#1a1a2e',
     completionCurrentBg: '#333355',
     completionMetaBg: '#1a1a2e',
@@ -308,7 +315,7 @@ export const LIGHT_THEME: Theme = {
     // same disease as dark: muted was `#7A5A0F` (gold-brown). True neutral —
     // the statusFg `#333333` family's lighter step, CSS `dimgray`.
     muted: '#696969',
-    bg: 'white',
+    bg: 'transparent',
     completionBg: '#F5F5F5',
     completionCurrentBg: mix('#F5F5F5', '#A0651C', 0.25),
     completionMetaBg: '#F5F5F5',
@@ -445,7 +452,13 @@ export function fromSkin(
 
   const accent = c('ui_accent') ?? c('banner_accent') ?? d.color.accent
   const bannerAccent = c('banner_accent') ?? c('banner_title') ?? d.color.accent
-  const muted = c('banner_dim') ?? d.color.muted
+  // Design pass (Appendix C precondition): `muted` is the transcript's "merely
+  // happened" NEUTRAL — it must NOT borrow `banner_dim` (the stock skin's dim
+  // GOLD banner shade; the Ink engine still uses it for its banner-tinted dim).
+  // Borrowing it re-golded every dim surface in the live app and made the hero
+  // color the wallpaper. Skins that want a custom transcript dim ship the
+  // dedicated `ui_muted` key; everything else gets the theme's true neutral.
+  const muted = c('ui_muted') ?? d.color.muted
   const completionBg = c('completion_menu_bg') ?? d.color.completionBg
 
   const completionCurrentBg =
diff --git a/ui-opentui/src/test/inkBudget.test.tsx b/ui-opentui/src/test/inkBudget.test.tsx
index 2e24d4c3810..fa4ddcd1d24 100644
--- a/ui-opentui/src/test/inkBudget.test.tsx
+++ b/ui-opentui/src/test/inkBudget.test.tsx
@@ -50,9 +50,9 @@ describe('theme — muted is a true neutral, not darker gold (design-pass precon
     expect(isAchromatic(DARK_THEME.color.sessionBorder)).toBe(true)
   })
 
-  test('bg token: true black (dark) / white (light) by CSS name', () => {
-    expect(DARK_THEME.color.bg).toBe('black')
-    expect(LIGHT_THEME.color.bg).toBe('white')
+  test('bg token: TRANSPARENT by default — the terminal owns the canvas (glitch decision)', () => {
+    expect(DARK_THEME.color.bg).toBe('transparent')
+    expect(LIGHT_THEME.color.bg).toBe('transparent')
   })
 
   test('fromSkin: skins may override bg via ui_bg; default stays the theme bg', () => {
@@ -60,8 +60,14 @@ describe('theme — muted is a true neutral, not darker gold (design-pass precon
     expect(fromSkin({}, {}).color.bg).toBe(DARK_THEME.color.bg)
   })
 
-  test('skin mapping intact: banner_dim still re-points muted (skins keep their dim)', () => {
-    expect(fromSkin({ banner_dim: '#445566' }, {}).color.muted).toBe('#445566')
+  test('muted no longer borrows banner_dim (the stock skin ships GOLD there — the live re-gold bug)', () => {
+    // The default Hermes skin sends banner_dim '#B8860B'; borrowing it for
+    // muted re-golded every dim surface in the live app. It must stay neutral.
+    expect(fromSkin({ banner_dim: '#B8860B' }, {}).color.muted).toBe(DARK_THEME.color.muted)
+  })
+
+  test('skins keep a dedicated transcript-dim override: ui_muted', () => {
+    expect(fromSkin({ ui_muted: '#445566' }, {}).color.muted).toBe('#445566')
   })
 })
 
diff --git a/ui-opentui/src/view/header.tsx b/ui-opentui/src/view/header.tsx
index a241a97bd17..742d134c953 100644
--- a/ui-opentui/src/view/header.tsx
+++ b/ui-opentui/src/view/header.tsx
@@ -24,6 +24,9 @@ export function Header(props: { store: SessionStore }) {
   // Root canvas paint — best-effort (a styling miss must never crash chrome).
   createEffect(() => {
     const bg = theme().color.bg
+    // Default is `transparent` = leave the terminal's background alone; only a
+    // skin's explicit ui_bg paints the canvas.
+    if (bg === 'transparent') return
     try {
       renderer.setBackgroundColor(bg)
     } catch {