diff --git a/static/js/conversation.js b/static/js/conversation.js
index 5de0483..3f22d30 100644
--- a/static/js/conversation.js
+++ b/static/js/conversation.js
@@ -675,6 +675,10 @@ $('s-import-voices-file')?.addEventListener('change', async function () {
   function resetConversationInput(statusText = 'Ready') {
     liveInterimText = '';
     previewTranscribing = false;
+    // Red = hot (live or recording); the label/pressed state carries it for non-colour users.
+    const hot = liveMicEnabled || micBtn.classList.contains('recording');
+    micBtn.setAttribute('aria-pressed', hot ? 'true' : 'false');
+    micBtn.setAttribute('aria-label', tr(hot ? 'Stop microphone' : 'Start microphone'));
     isProcessing = false;
     micBtn.classList.remove('processing', 'recording');
     micIcon.className = 'mdi mdi-microphone';
@@ -846,12 +850,19 @@ $('s-import-voices-file')?.addEventListener('change', async function () {
       toast('Microphone unavailable — browser requires a secure context (HTTPS or localhost). ' +
             'Access the app via http://localhost:7890 or enable it in chrome://flags/#unsafely-treat-insecure-origin-as-secure', 'error', 8000);
       return;
+  function micOffAfterFailure() { // never leave the button red when no mic is open
+    liveMicEnabled = false;
+    micBtn.classList.remove('recording');
+    setLiveMicUi('Mic off');
+  }
+
     }
     let stream;
     try {
       stream = await navigator.mediaDevices.getUserMedia({ audio: true });
     } catch(e) {
       toast('Microphone access denied: ' + e.message, 'error');
+      micOffAfterFailure();
       return;
     }
 
@@ -859,6 +870,7 @@ $('s-import-voices-file')?.addEventListener('change', async function () {
     previewTranscribing = false;
     vadHadSpeech = false;
     vadLastVoiceMs = 0;
+      micOffAfterFailure();
     vadSpeechStartMs = 0;
     cancelNextBlob = false;
     recChunks = [];
@@ -1020,6 +1032,7 @@ $('s-import-voices-file')?.addEventListener('change', async function () {
 
   // ── Send turn via SSE ─────────────────────────────────────────────────────
   // Decode a recorded blob (webm/opus, ogg, …) in the browser and re-encode it
+    setLiveMicUi();
   // as a 16 kHz mono WAV. This sidesteps server-side ffmpeg, whose webm/EBML
   // parser fails on some platforms (ARM64): "EBML header parsing failed".
   // Returns a WAV Blob, or null if decoding isn't possible (caller falls back).
diff --git a/static/js/i18n.js b/static/js/i18n.js
index 854bcfe..4ed657d 100644
--- a/static/js/i18n.js
+++ b/static/js/i18n.js
@@ -94,6 +94,8 @@ const I18N_DICT = {
     'Thinking': 'Denken',
     'on': 'an', 'off': 'aus',
     'Off = faster answers. On = better reasoning but slower, and some models may return an empty reply.': 'Aus = schnellere Antworten. An = besseres Schlussfolgern, aber langsamer; manche Modelle liefern eine leere Antwort.',
+    // Conversation mic button
+    'Stop microphone': 'Mikrofon stoppen', 'Start microphone': 'Mikrofon starten',
     // Conversation metrics view
     'Token Usage': 'Token-Verbrauch', 'Time (ms)': 'Zeit (ms)',
     'Prompt': 'Prompt', 'Completion': 'Completion',
diff --git a/static/style.css b/static/style.css
index 89469b3..5260161 100644
--- a/static/style.css
+++ b/static/style.css
@@ -4359,11 +4359,15 @@ code { background: var(--panel); border-radius: 4px; padding: 1px 5px; font-fami
   justify-content: center; transition: background .15s, transform .1s, box-shadow .15s;
 }
 .conv-mic-btn:hover { background: #1d4ed8; }
-.conv-mic-btn.live { background: var(--accent); border-color: var(--accent); box-shadow: 0 0 0 4px rgba(37,99,235,.16); }
-.conv-mic-btn.live:not(.processing) { animation: convPulse 1.4s infinite; }
-.conv-mic-btn.recording:not(.live) { background: var(--red); border-color: var(--red); animation: convPulse 1s infinite; }
+.conv-mic-btn.live { background: var(--red); border-color: var(--red); box-shadow: 0 0 0 4px rgba(220,38,38,.16); }
+.conv-mic-btn.live:hover, .conv-mic-btn.recording:hover { filter: brightness(.9); }
+.conv-mic-btn.recording:not(.live) { background: var(--red); border-color: var(--red); }
+@media (prefers-reduced-motion: no-preference) {
+  .conv-mic-btn.live:not(.processing) { animation: convPulse 1.4s infinite; }
+  .conv-mic-btn.recording:not(.live) { animation: convPulse 1s infinite; }
+}
 .conv-mic-btn.processing { background: var(--yellow); border-color: var(--yellow); cursor: pointer; }
-.conv-mic-btn.processing.live { background: var(--accent); border-color: var(--accent); }
+.conv-mic-btn.processing.live { background: var(--red); border-color: var(--red); }
 @keyframes convPulse { 0%,100% { box-shadow: 0 0 0 0 rgba(220,38,38,.4); } 50% { box-shadow: 0 0 0 8px rgba(220,38,38,0); } }
 .conv-mic-timer { font-size: 13px; font-variant-numeric: tabular-nums; color: var(--red); min-width: 36px; text-align: right; }
 .conv-vad-label { display: flex; align-items: center; gap: 4px; font-size: 11px; color: var(--subtext); cursor: pointer; white-space: nowrap; user-select: none; }
diff --git a/tests/conversation-mic.spec.js b/tests/conversation-mic.spec.js
new file mode 100644
index 0000000..b3b4e7f
--- /dev/null
+++ b/tests/conversation-mic.spec.js
@@ -0,0 +1,54 @@
+// @ts-check
+// Conversation mic button: red while hot, blue when off, aria toggles (all /api routes mocked).
+const { test, expect } = require('./_guard');
+
+async function boot(page, { denied = false } = {}) {
+  await page.route('**/api/**', route => route.request().method() === 'GET' ? route.fulfill({ json: {} }) : route.fulfill({ json: { ok: true } }));
+  await page.route('**/static/dist/main.min.js*', r => r.abort());
+  await page.addInitScript(d => {
+    const gum = d ? () => Promise.reject(new Error('denied')) : () => Promise.resolve({ getTracks: () => [{ stop() {} }] });
+    Object.defineProperty(navigator, 'mediaDevices', { value: { getUserMedia: gum }, configurable: true });
+    window.MediaRecorder = class { constructor() { this.state = 'inactive'; this.mimeType = 'audio/webm'; }
+      start() { this.state = 'recording'; } stop() { this.state = 'inactive'; setTimeout(() => this.onstop && this.onstop(), 20); } };
+    window.MediaRecorder.isTypeSupported = () => true;
+  }, denied);
+  await page.goto('/', { waitUntil: 'domcontentloaded' });
+  await page.waitForFunction(() => typeof window.navTo === 'function', null, { timeout: 15_000 });
+  await page.waitForSelector('#app-skeleton', { state: 'detached', timeout: 15_000 });
+  await page.evaluate(() => window.navTo('s-conversation'));
+}
+const bg = async (/** @type {import('@playwright/test').Page} */ page) => { await page.mouse.move(0, 0); return page.locator('#conv-mic-btn').evaluate(e => getComputedStyle(e).backgroundColor); };
+
+test('mic is blue and unpressed when off, red and pressed when hot, back to blue after stop', async ({ page }) => {
+  await boot(page);
+  const btn = page.locator('#conv-mic-btn');
+  await expect(btn).toHaveAttribute('aria-pressed', 'false');
+  await expect(btn).toHaveAttribute('aria-label', 'Start microphone');
+  const blue = await bg(page);
+  await btn.click();
+  await expect(btn).toHaveAttribute('aria-pressed', 'true');
+  await expect(btn).toHaveAttribute('aria-label', 'Stop microphone');
+  await expect(page.locator('#conv-mic-status')).toHaveText('Listening…');
+  await expect.poll(() => bg(page)).not.toBe(blue);
+  await expect.poll(async () => { const [r, g, b] = (await bg(page)).match(/\d+/g).map(Number); return r > 200 && g < 90 && b < 90; }).toBe(true); // --red
+  await btn.click();
+  await expect(btn).toHaveAttribute('aria-pressed', 'false');
+  await expect(page.locator('#conv-mic-status')).toHaveText('Mic off');
+  await expect.poll(() => bg(page)).toBe(blue);
+});
+
+test('mic never stays red when microphone access is denied', async ({ page }) => {
+  await boot(page, { denied: true });
+  const btn = page.locator('#conv-mic-btn');
+  const blue = await bg(page);
+  await btn.click();
+  await expect(btn).toHaveAttribute('aria-pressed', 'false');
+  await expect(page.locator('#conv-mic-status')).toHaveText('Mic off');
+  await expect.poll(() => bg(page)).toBe(blue);
+});
+
+test('German mic labels', async ({ page }) => {
+  await page.addInitScript(() => { try { localStorage.setItem('app-lang', 'de'); } catch (e) {} });
+  await boot(page);
+  await expect(page.locator('#conv-mic-btn')).toHaveAttribute('aria-label', 'Mikrofon starten');
+});