diff --git a/App.tsx b/App.tsx
index 1d4f3b3..b7ce447 100644
--- a/App.tsx
+++ b/App.tsx
@@ -764,6 +764,29 @@ export default function App() {
     lastStepRef.current = 0;
     setUndoDepth(0);
   };
+  // FX's MONOCHROME switch: not a look of its own — it swaps the base filter for
+  // the mono stock and swaps right back. Adjustments are never touched, so a knob
+  // turned while it is on survives the round trip.
+  const monoOn = selectedRecipe?.baseFilter === 'monochrome';
+  const monoPrevRef = useRef<Recipe | null>(null);
+
+  const handleToggleMono = () => {
+    commit(true, () => {
+      if (selectedRecipe?.baseFilter === 'monochrome') {
+        const back = monoPrevRef.current ?? filmSimToRecipe(FILM_SIMS.find((f) => f.id === 'sim-provia')!);
+        monoPrevRef.current = null;
+        setSelectedRecipe(back);
+      } else {
+        monoPrevRef.current = selectedRecipe;
+        setSelectedRecipe({
+          ...(selectedRecipe ?? filmSimToRecipe(FILM_SIMS[0])),
+          id: 'mono',
+          name: 'MONOCHROME',
+          baseFilter: 'monochrome',
+        });
+      }
+    });
+  };
   const applyLook = (l: Look) => {
     setSelectedRecipe(l.recipe);
     setAdjustments(l.adjustments);
@@ -1963,6 +1986,8 @@ export default function App() {
               openParam={openParamKey}
               onOpenParamChange={setOpenParamKey}
               currentBaseFilter={selectedRecipe?.baseFilter}
+              monoOn={monoOn}
+              onToggleMono={handleToggleMono}
               onCreateRecipe={handleCreateRecipe}
               editingRecipe={editingRecipe}
               onCloseEdit={() => setEditingRecipe(null)}
diff --git a/src/components/AdjustmentPanel.tsx b/src/components/AdjustmentPanel.tsx
index f526143..a759f15 100644
--- a/src/components/AdjustmentPanel.tsx
+++ b/src/components/AdjustmentPanel.tsx
@@ -80,6 +80,10 @@ interface AdjustmentPanelProps {
   // Base filter of the currently applied recipe — seeds the CREATE modal's
   // SIMULATION row so quick-input starts from the active look.
   currentBaseFilter?: BaseFilter;
+  // FX tab MONOCHROME: a switch, not a look — on it swaps the base filter for
+  // the mono stock, off it hands back the one that was there.
+  monoOn: boolean;
+  onToggleMono: () => void;
   // CREATE quick-input saves a brand-new recipe (name + adjustments from the
   // modal) and applies it, unlike onSaveRecipe which snapshots the live state.
   onCreateRecipe: (recipe: Omit<Recipe, 'id' | 'isCustom'>) => void;
@@ -243,6 +247,8 @@ export default function AdjustmentPanel({
   openParam,
   onOpenParamChange,
   currentBaseFilter,
+  monoOn,
+  onToggleMono,
   onCreateRecipe,
   editingRecipe,
   onCloseEdit,
@@ -896,7 +902,12 @@ export default function AdjustmentPanel({
         ]);
 
       case 'filters':
-        return chipRow(paramChips(paramDefs.filters));
+        // MONOCHROME leads the strip: a switch that swaps the base filter for
+        // the mono stock and swaps right back, so it never touches a knob.
+        return chipRow([
+          { key: 'mono', label: 'MONOCHROME', active: monoOn, amberValue: monoOn, onPress: onToggleMono },
+          ...paramChips(paramDefs.filters),
+        ]);
 
       case 'frame':
         // FRAME -> WATERMARK: the sub-panel row (breadcrumb back to the frames).
diff --git a/src/types/index.ts b/src/types/index.ts
index 0a0fff6..8280081 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -62,7 +62,7 @@ export const MIN_CROP_FRAC = 0.08;
 // cool tint in shade, plus a seasonal atmospheric haze/fog veil.
 export type CinemaSeason = 'spring' | 'summer' | 'autumn' | 'winter';
 
-export type BaseFilter = 'classic-neg' | 'classic-chrome' | 'provia' | 'velvia' | 'astia' | 'eterna' | 'monochrome' | 'leica' | 'leica-vivid' | 'none';
+export type BaseFilter = 'classic-neg' | 'classic-chrome' | 'classic-vivid' | 'provia' | 'velvia' | 'astia' | 'eterna' | 'monochrome' | 'leica' | 'leica-vivid' | 'none';
 
 export interface ColorAdjustments {
   exposure: number; // -10 to +10 (mapped to matrix multiplier or offset)
diff --git a/src/utils/colorUtils.ts b/src/utils/colorUtils.ts
index 4a69a24..1de5316 100644
--- a/src/utils/colorUtils.ts
+++ b/src/utils/colorUtils.ts
@@ -120,6 +120,16 @@ export function getSkiaColorMatrix(baseFilter: BaseFilter, adj: ColorAdjustments
       0.0652, 0.3973, 0.5575, 0, -0.0100,
       0, 0, 0, 1, 0,
     ];
+  } else if (baseFilter === 'classic-vivid') {
+    // Classic Vivid: the Classic Chrome blue row kept verbatim — skies stay the
+    // same muted teal/cyan — with the red and green rows taken from Velvia, so
+    // everything that is not blue reads loud.
+    matrix = [
+      1.3895, -0.2540, -0.0256, 0, -0.0550,   // R — velvia
+      -0.0772, 1.2355, -0.0261, 0, -0.0661,   // G — velvia
+      0.0652, 0.3973, 0.5575, 0, -0.0100,     // B — classic-chrome (nguyên bản)
+      0, 0, 0, 1, 0,
+    ];
   } else if (baseFilter === 'astia') {
     // Astia (Soft): gentler than standard — contrast below neutral (shadows
     // lift, highlights ease off) and colour held back, with a faint warm/pink
diff --git a/src/utils/defaultRecipes.ts b/src/utils/defaultRecipes.ts
index 22cb950..700978f 100644
--- a/src/utils/defaultRecipes.ts
+++ b/src/utils/defaultRecipes.ts
@@ -41,6 +41,7 @@ export const FILM_SIMS: FilmSim[] = [
   { id: 'sim-provia', name: 'PROVIPES', baseFilter: 'provia', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-velvia', name: 'VELVIPES', baseFilter: 'velvia', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-classic-chrome', name: 'CLASSIC CHRIPES', baseFilter: 'classic-chrome', adjustments: { ...DEFAULT_ADJUSTMENTS } },
+  { id: 'sim-classic-vivid', name: 'CLASSIC VIVIDIPES', baseFilter: 'classic-vivid', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-classic-neg', name: 'CLASSIC NEGIPES', baseFilter: 'classic-neg', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-astia', name: 'ASTIPES', baseFilter: 'astia', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-eterna', name: 'ETERNIPES', baseFilter: 'eterna', adjustments: { ...DEFAULT_ADJUSTMENTS } },
diff --git a/src/utils/toneShader.ts b/src/utils/toneShader.ts
index 2325f36..2008728 100644
--- a/src/utils/toneShader.ts
+++ b/src/utils/toneShader.ts
@@ -188,6 +188,9 @@ export interface ToneUniforms {
 // without also moving the other.
 const FILM_TONE: Partial<Record<BaseFilter, Partial<ToneUniforms>>> = {
   'classic-chrome': { sh: -0.28 },
+  // Classic Vivid keeps Chrome's dived shadow: the shadow pull belongs to the
+  // stock, not to the matrix rows it borrows from Velvia.
+  'classic-vivid': { sh: -0.28 },
   'classic-neg': { shT: [-0.018, 0.009, 0.013], hlT: [0.024, 0.008, -0.012] },
   // Acros. A black-and-white stock IS its grey ramp, so this entry only shapes
   // the two ENDS and leaves the middle an identity: a smooth shadow toe that