diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0cddf6b..37ccfef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -58,6 +58,52 @@ Migration.
 - Doku-Drift zum Capabilities-Endpunkt in CLAUDE.md und EXTRAKTIONSPLAN
   bereinigt.
 
+## ui/v0.9.0 — 2026-10-11
+
+### @basicbar/ui
+
+Anlass: abstimmbar #178 (Kontrast) brauchte einen Formularfeld-Rahmen mit
+≥ 3:1 (WCAG 1.4.11) und Fehlertext mit ≥ 4.5:1 und überschrieb dafür per CSS
+den Rahmen des Paket-Editors. Beides wird jetzt Paket-Funktion.
+
+- **Neue semantische Farben `field` und `danger`** im Preset (mit
+  `/ <alpha-value>`, also z. B. `border-field/50`, `text-danger`). Sie lesen
+  die CSS-Variablen `--bb-field-border` und `--bb-danger` (OKLCH-Kanäle ohne
+  `oklch()`), deren Defaults `base.css` setzt (hell unter `:root`, dunkel unter
+  `:root.dark`). Defaults und berechnete Kontraste stehen als Kommentar in
+  `base.css`: `field` hell `0.6 0 0` (3.5–3.95:1 auf Weiß/slate-50/100), dunkel
+  `0.56 0 0` (≥ 3.76:1 auf slate-900/950); `danger` hell `0.55 0.235 27`
+  (≥ 4.74:1), dunkel `0.704 0.191 22.216` = red-400 (≥ 5.03:1).
+- **Komponenten nutzen die Tokens:** Rahmen von `RichTextEditor` (Fokusring
+  unverändert) und Standard-Input von `TranslatableField` → `border-field`
+  (sichtbar etwas dunkler als vorher); Pflicht-Sternchen, Übersetzungsfehler und
+  „Pflichtfeld“-Meldung in `TranslatableField` sowie die Fehlermeldung der
+  Übersetzungsleiste → `text-danger` (vorher rose-500/600/400).
+- **Preset-Kommentar korrigiert:** „slate-400 ≥ 4.5:1 auf Weiß“ galt nicht für
+  jede Rampe. Gedämpfter Text ist in beiden Themes gegen Seite und Karten auf
+  ≥ 4.5:1 zu prüfen.
+
+Tönen: Die Defaults sind neutral. Ein Tool färbt sie ein, indem es die
+Variablen in seinem eigenen (ungeschichteten) CSS überschreibt, z. B.
+
+```css
+:root { --bb-field-border: 0.62 0.011 220; --bb-danger: 0.55 0.235 27; }
+:root.dark { --bb-field-border: 0.56 0.011 220; }
+```
+
+und die Kontraste (field ≥ 3:1, danger ≥ 4.5:1) gegen die eigenen Hintergründe
+nachrechnet.
+
+Migration:
+
+1. Tarball auf `ui/v0.9.0`, Vite-Dep-Cache leeren.
+2. Eigene Overrides des Editor-Rahmens (z. B. `.xy-rte > div.rounded-lg
+   { border-color: … }`) entfernen; stattdessen `--bb-field-border` setzen,
+   falls der Default nicht passt. Eine lokale `field`-Farbe im Tool-Preset
+   durch die Variable ersetzen.
+3. Optional: lokale Fehlerrot-Muster (`text-red-600 dark:text-red-400` o. ä.)
+   durch `text-danger` ersetzen.
+
 ## ui/v0.8.0 — 2026-10-10
 
 ### @basicbar/ui
diff --git a/packages/ui/README.md b/packages/ui/README.md
index dd11bca..5a24cf6 100644
--- a/packages/ui/README.md
+++ b/packages/ui/README.md
@@ -12,6 +12,9 @@ Tools identisch aussehen, übergeben sie dieselbe Ramp.
   (Plus Jakarta Sans Variable), Dark Mode per `.dark`-Klasse, Motion-Tokens
   (`pop`, `fade-up`, `out-quart`). Die `slate`/`brand`-Ramps übergibt das Tool
   (OKLCH, Konventionen im Preset-Docstring).
+  Dazu die semantischen Farben `field` (Formularrahmen, ≥ 3:1) und `danger`
+  (Fehlertext, ≥ 4.5:1) über die Variablen `--bb-field-border`/`--bb-danger`
+  (Defaults in `base.css`, vom Tool überschreibbar).
 - **`@basicbar/ui/base.css`** — gemeinsame Basis-Styles (`@layer base` plus
   ungelayerte ProseMirror-Regeln): Canvas hell/dunkel,
   `accent-color`, `::selection`, konsistenter `:focus-visible`-Ring
diff --git a/packages/ui/base.css b/packages/ui/base.css
index 995284f..d605e01 100644
--- a/packages/ui/base.css
+++ b/packages/ui/base.css
@@ -16,9 +16,29 @@
      `color-scheme` on <html>; these rules cover the pre-React first paint. */
   :root {
     color-scheme: light;
+    /* Semantic colour tokens (Tailwind colours `field` and `danger`, see
+       tailwind-preset.js). Values are OKLCH channels without `oklch()` so the
+       preset can append `/ <alpha-value>`. Neutral defaults: a tool tints
+       them by overriding the variables in its own (unlayered) CSS, e.g.
+       `:root { --bb-field-border: 0.6 0.011 220; }`, and re-checks the ratios.
+       Computed WCAG contrast (sRGB, clamped):
+       --bb-field-border (form-control boundary, WCAG 1.4.11 needs >=3:1)
+         light 0.6 0 0: 3.95 on white, 3.78 on slate-50, 3.54 on slate-100
+         dark 0.56 0 0: 4.17 on slate-950/#090e10, 3.76 on slate-900,
+                        3.13 on slate-800
+       --bb-danger (error text, WCAG 1.4.3 needs >=4.5:1)
+         light 0.55 0.235 27: 5.29 on white, 5.07 on slate-50, 4.74 on slate-100
+         dark 0.704 0.191 22.216 (red-400): 6.7 on slate-950, 6.04 on slate-900,
+                                            5.03 on slate-800
+       (slate ramps of abstimmbar and ausleihbar; both give the same ratios to
+       within 0.01.) */
+    --bb-field-border: 0.6 0 0;
+    --bb-danger: 0.55 0.235 27;
   }
   :root.dark {
     color-scheme: dark;
+    --bb-field-border: 0.56 0 0;
+    --bb-danger: 0.704 0.191 22.216;
   }
 
   /* Ink on white in light mode; a near-black canvas in dark mode. The accent
diff --git a/packages/ui/package-lock.json b/packages/ui/package-lock.json
index 7163739..081afff 100644
--- a/packages/ui/package-lock.json
+++ b/packages/ui/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@basicbar/ui",
-  "version": "0.8.0",
+  "version": "0.9.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@basicbar/ui",
-      "version": "0.8.0",
+      "version": "0.9.0",
       "license": "Apache-2.0",
       "dependencies": {
         "@tiptap/extension-bold": "^3.27.2",
diff --git a/packages/ui/package.json b/packages/ui/package.json
index b7c1f89..9b65461 100644
--- a/packages/ui/package.json
+++ b/packages/ui/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@basicbar/ui",
-  "version": "0.8.0",
+  "version": "0.9.0",
   "description": "Design-System-Basis der virtUOS -bar-Tools: Tailwind-Preset, Basis-Styles, Theme (Dark Mode), i18n-Bootstrap, contentLang, TranslatableField, Preferences, RichText; RichTextEditor (TipTap) als eigener Entry",
   "license": "Apache-2.0",
   "author": "Universität Osnabrück (virtUOS)",
diff --git a/packages/ui/src/RichTextEditor.tsx b/packages/ui/src/RichTextEditor.tsx
index c5a7e3e..1775c7c 100644
--- a/packages/ui/src/RichTextEditor.tsx
+++ b/packages/ui/src/RichTextEditor.tsx
@@ -313,7 +313,7 @@ export function RichTextEditor({
 
   return (
     <div
-      className={`rounded-lg border border-slate-300 dark:border-slate-700 focus-within:ring-2 focus-within:ring-brand-600 focus-within:ring-offset-2 focus-within:ring-offset-white dark:focus-within:ring-offset-slate-950 ${
+      className={`rounded-lg border border-field focus-within:ring-2 focus-within:ring-brand-600 focus-within:ring-offset-2 focus-within:ring-offset-white dark:focus-within:ring-offset-slate-950 ${
         editable ? "" : "bg-slate-50 dark:bg-slate-900"
       }`}
     >
diff --git a/packages/ui/src/TranslatableField.tsx b/packages/ui/src/TranslatableField.tsx
index f9f6fb3..4494aab 100644
--- a/packages/ui/src/TranslatableField.tsx
+++ b/packages/ui/src/TranslatableField.tsx
@@ -61,7 +61,7 @@ export interface RenderInputArgs {
 }
 
 const DEFAULT_INPUT_CLASS =
-  "w-full rounded-lg border border-slate-300 dark:border-slate-700 bg-white px-3 py-2 text-sm text-slate-900 placeholder:text-slate-400 focus:border-brand-600 focus:outline-none focus:ring-1 focus:ring-brand-600 dark:bg-slate-900 dark:text-slate-100";
+  "w-full rounded-lg border border-field bg-white px-3 py-2 text-sm text-slate-900 placeholder:text-slate-400 focus:border-brand-600 focus:outline-none focus:ring-1 focus:ring-brand-600 dark:bg-slate-900 dark:text-slate-100";
 
 export interface TranslatableFieldProps {
   /** Visible label above the field; omit for compact inline uses (the
@@ -260,7 +260,7 @@ export function TranslatableField({
             <span className="flex items-center gap-1">
               <label id={labelId} htmlFor={inputId} className={labelClassName}>
                 {label}
-                {required && <span className="text-rose-500"> *</span>}
+                {required && <span className="text-danger"> *</span>}
               </label>
               {labelAddon}
             </span>
@@ -384,14 +384,14 @@ export function TranslatableField({
           )}
         </div>
       )}
-      {translateError && <p className="mt-1 text-rose-500">{translateError}</p>}
+      {translateError && <p className="mt-1 text-danger">{translateError}</p>}
       {hint && (
         <p id={hintId} className="mt-1 text-slate-600 dark:text-slate-300">
           {hint}
         </p>
       )}
       {canonicalEmpty && (
-        <p id={requiredId} className="mt-1 text-rose-600 dark:text-rose-400">
+        <p id={requiredId} className="mt-1 text-danger">
           {t("A value in {{language}} is required.", {
             language: defaultContentLangLabel(),
           })}
diff --git a/packages/ui/src/TranslationForm.tsx b/packages/ui/src/TranslationForm.tsx
index 33f3d2c..0c961ad 100644
--- a/packages/ui/src/TranslationForm.tsx
+++ b/packages/ui/src/TranslationForm.tsx
@@ -450,7 +450,7 @@ export function TranslationFormProvider({
   const renderControls = (withHandle: boolean) => (
     <>
       {error && (
-        <span className="rounded-md bg-white px-2 py-1 text-xs text-rose-600 shadow dark:bg-slate-800 dark:text-rose-400">
+        <span className="rounded-md bg-white px-2 py-1 text-xs text-danger shadow dark:bg-slate-800">
           {error}
         </span>
       )}
diff --git a/packages/ui/tailwind-preset.js b/packages/ui/tailwind-preset.js
index 6ce74cc..3b6f8c0 100644
--- a/packages/ui/tailwind-preset.js
+++ b/packages/ui/tailwind-preset.js
@@ -11,7 +11,14 @@
  * Ramp conventions (keep these when authoring a tool ramp, see the READMEs of
  * the existing tools; values are OKLCH and tuned for WCAG AA):
  * - `slate` is the neutral ramp, usually hue-tinted toward the accent
- *   (warm for honey, cool for green). slate-400 on white stays ≥4.5:1.
+ *   (warm for honey, cool for green). Muted text (typically slate-400/500)
+ *   must reach ≥4.5:1 on the page and card backgrounds in BOTH themes — a
+ *   single ramp value often can't, so check light and dark and, if needed,
+ *   drive it through a CSS variable that dark mode lifts.
+ * - Form-control borders and error text are NOT ramp steps: use the `field`
+ *   and `danger` tokens below (variables `--bb-field-border` / `--bb-danger`
+ *   with contrast-checked defaults in base.css; tools override the variables
+ *   to tint them).
  * - `brand` is the single accent: CTAs use brand-400 with dark ink text,
  *   brand-600 is the focus/selection color (≥3:1 non-text on white),
  *   brand-700 is accent text on white (≥4.5:1).
@@ -55,7 +62,13 @@ export function createPreset({ colors } = {}) {
             "sans-serif",
           ],
         },
-        colors,
+        colors: {
+          // Semantic tokens; defaults live in base.css. Tools tint them by
+          // overriding the CSS variables, not by redefining `field`/`danger`.
+          field: "oklch(var(--bb-field-border) / <alpha-value>)",
+          danger: "oklch(var(--bb-danger) / <alpha-value>)",
+          ...colors,
+        },
         transitionTimingFunction: {
           "out-quart": "cubic-bezier(0.25, 1, 0.5, 1)",
         },