diff --git a/src/openforms/js/components/admin/form_design/Editor.js b/src/openforms/js/components/admin/form_design/Editor.js
index 3ae90687d2..20606f58b4 100644
--- a/src/openforms/js/components/admin/form_design/Editor.js
+++ b/src/openforms/js/components/admin/form_design/Editor.js
@@ -9,6 +9,9 @@ const TinyMCEEditor = ({content, onEditorChange}) => {
   const editorRef = useRef(null);
   const tinyMceUrl = useContext(TinyMceContext);
   const intl = useIntl();
+  // TODO Django 4.2: use explicit theme names rather than the media query approach:
+  // https://github.com/django/django/blob/main/django/contrib/admin/static/admin/css/dark_mode.css#L36
+  const useDarkMode = window.matchMedia('(prefers-color-scheme: dark)').matches;
 
   return (
     <>
@@ -16,7 +19,12 @@ const TinyMCEEditor = ({content, onEditorChange}) => {
         tinymceScriptSrc={tinyMceUrl}
         onInit={(evt, editor) => (editorRef.current = editor)}
         value={content}
-        init={{...tinyMceConfig, language: intl.locale}}
+        init={{
+          ...tinyMceConfig,
+          language: intl.locale,
+          skin: useDarkMode ? 'oxide-dark' : 'oxide',
+          content_css: useDarkMode ? 'dark' : 'default',
+        }}
         onEditorChange={onEditorChange}
       />
     </>
diff --git a/src/openforms/js/components/form/textfield.js b/src/openforms/js/components/form/textfield.js
index e771302b27..3a41991c12 100644
--- a/src/openforms/js/components/form/textfield.js
+++ b/src/openforms/js/components/form/textfield.js
@@ -1,5 +1,4 @@
 import {Formio} from 'react-formio';
-
 import {DEFAULT_TEXT_TABS} from './edit/tabs';
 
 class TextField extends Formio.Components.components.textfield {
diff --git a/src/openforms/js/index.js b/src/openforms/js/index.js
index f881ac852c..9738775e6d 100644
--- a/src/openforms/js/index.js
+++ b/src/openforms/js/index.js
@@ -1,5 +1,5 @@
 import {Formio} from 'react-formio';
-
+import './initTinymce';
 import './components';
 import OpenForms from './formio_module';
 
diff --git a/src/openforms/js/initTinymce.js b/src/openforms/js/initTinymce.js
new file mode 100644
index 0000000000..3c124cfe89
--- /dev/null
+++ b/src/openforms/js/initTinymce.js
@@ -0,0 +1,91 @@
+// Taken from https://github.com/jazzband/django-tinymce/blob/master/tinymce/static/django_tinymce/init_tinymce.js
+// Updated to add dark theme detection (L35-44)
+
+'use strict';
+
+{
+  function initTinyMCE(el) {
+    if (el.closest('.empty-form') === null) {
+      // Don't do empty inlines
+      var mce_conf = JSON.parse(el.dataset.mceConf);
+
+      // There is no way to pass a JavaScript function as an option
+      // because all options are serialized as JSON.
+      const fns = [
+        'color_picker_callback',
+        'file_browser_callback',
+        'file_picker_callback',
+        'images_dataimg_filter',
+        'images_upload_handler',
+        'paste_postprocess',
+        'paste_preprocess',
+        'setup',
+        'urlconverter_callback',
+      ];
+      fns.forEach(fn_name => {
+        if (typeof mce_conf[fn_name] != 'undefined') {
+          if (mce_conf[fn_name].includes('(')) {
+            mce_conf[fn_name] = eval('(' + mce_conf[fn_name] + ')');
+          } else {
+            mce_conf[fn_name] = window[mce_conf[fn_name]];
+          }
+        }
+      });
+
+      // TODO Django 4.2: use explicit theme names rather than the media query approach:
+      // https://github.com/django/django/blob/main/django/contrib/admin/static/admin/css/dark_mode.css#L36
+      const useDarkMode = window.matchMedia('(prefers-color-scheme: dark)').matches;
+      mce_conf = {
+        ...mce_conf,
+        ...{
+          skin: useDarkMode ? 'oxide-dark' : 'oxide',
+          content_css: useDarkMode ? 'dark' : 'default',
+        },
+      };
+
+      const id = el.id;
+      if ('elements' in mce_conf && mce_conf['mode'] == 'exact') {
+        mce_conf['elements'] = id;
+      }
+      if (el.dataset.mceGzConf) {
+        tinyMCE_GZ.init(JSON.parse(el.dataset.mceGzConf));
+      }
+      if (!tinyMCE.get(id)) {
+        tinyMCE.init(mce_conf);
+      }
+    }
+  }
+
+  // Call function fn when the DOM is loaded and ready. If it is already
+  // loaded, call the function now.
+  // https://youmightnotneedjquery.com/#ready
+  function ready(fn) {
+    if (document.readyState !== 'loading') {
+      fn();
+    } else {
+      document.addEventListener('DOMContentLoaded', fn);
+    }
+  }
+
+  function initializeTinyMCE(element, formsetName) {
+    Array.from(element.querySelectorAll('.tinymce')).forEach(area => initTinyMCE(area));
+  }
+
+  ready(function () {
+    // initialize the TinyMCE editors on load
+    initializeTinyMCE(document);
+
+    // initialize the TinyMCE editor after adding an inline in the django admin context.
+    if (typeof django !== 'undefined' && typeof django.jQuery !== 'undefined') {
+      django.jQuery(document).on('formset:added', (event, $row, formsetName) => {
+        if (event.detail && event.detail.formsetName) {
+          // Django >= 4.1
+          initializeTinyMCE(event.target);
+        } else {
+          // Django < 4.1, use $row
+          initializeTinyMCE($row.get(0));
+        }
+      });
+    }
+  });
+}
diff --git a/src/openforms/scss/admin/_admin_theme.scss b/src/openforms/scss/admin/_admin_theme.scss
index ab584af493..3066bf13da 100644
--- a/src/openforms/scss/admin/_admin_theme.scss
+++ b/src/openforms/scss/admin/_admin_theme.scss
@@ -95,6 +95,11 @@ DO NOT PUT ANY TARGET APP-SPECIFIC RULES HERE.
     background-color: var(--form-input-bg);
   }
 
+  input[type='checkbox'],
+  input[type='radio'] {
+    color-scheme: dark;
+  }
+
   body #toolbar {
     background: var(--body-bg);
   }
diff --git a/src/openforms/scss/admin/_app_overrides.scss b/src/openforms/scss/admin/_app_overrides.scss
index b380bb899a..150f9c41eb 100644
--- a/src/openforms/scss/admin/_app_overrides.scss
+++ b/src/openforms/scss/admin/_app_overrides.scss
@@ -211,16 +211,16 @@ $djai-border-width: 8px;
     }
 
     // re-apply django admin styles
-    background-color: buttonface;
-    border: 1px solid #ccc;
+    background-color: var(--form-input-bg);
+    border: 1px solid var(--border-color);
     border-radius: 4px;
     padding: 5px 6px;
     margin-top: 0;
 
     &:focus {
       color: inherit;
-      background-color: buttonface;
-      border-color: #999;
+      background-color: var(--form-input-bg);
+      border-color: var(--border-color);
       box-shadow: none;
       outline: initial;
     }
diff --git a/src/openforms/scss/components/admin/_ReactModal.scss b/src/openforms/scss/components/admin/_ReactModal.scss
index 58b0fcaef9..936e339b1a 100644
--- a/src/openforms/scss/components/admin/_ReactModal.scss
+++ b/src/openforms/scss/components/admin/_ReactModal.scss
@@ -20,8 +20,8 @@
     position: absolute;
     width: 50vw;
     height: 50vh;
-    background: white;
-    border: solid 1px #eee;
+    background: var(--body-bg);
+    border: 1px solid var(--hairline-color);
     border-radius: 0;
     outline: none;
     padding: 20px;
diff --git a/src/openforms/scss/components/admin/_sdk-snippet.scss b/src/openforms/scss/components/admin/_sdk-snippet.scss
index 8afa0533c0..9144151ce7 100644
--- a/src/openforms/scss/components/admin/_sdk-snippet.scss
+++ b/src/openforms/scss/components/admin/_sdk-snippet.scss
@@ -3,11 +3,15 @@
     display: inline-block;
     padding-top: 10px;
     padding-bottom: 10px;
-    background-color: #efefef;
+    background-color: var(--form-input-bg);
+    border-style: solid;
+    border-width: thin;
+    border-color: var(--border-color);
 
     pre {
       font-size: 100%;
       margin-bottom: 0;
+      color: var(--body-fg);
     }
   }
 
diff --git a/src/openforms/scss/components/builder/_builder.scss b/src/openforms/scss/components/builder/_builder.scss
index 5d6ee89457..c25cd56aa5 100644
--- a/src/openforms/scss/components/builder/_builder.scss
+++ b/src/openforms/scss/components/builder/_builder.scss
@@ -69,7 +69,8 @@ div.flatpickr-calendar.open {
   padding-top: 10px;
 }
 
-[ref='editForm'] {
+[ref='editForm'],
+[ref='component'] {
   .choices__list {
     &--dropdown {
       background-color: var(--body-bg);
@@ -226,4 +227,8 @@ div.flatpickr-calendar.open {
       }
     }
   }
+
+  .formio-button-add-another {
+    color: var(--body-fg) !important;
+  }
 }
diff --git a/src/openforms/scss/components/builder/_formio-component-file.scss b/src/openforms/scss/components/builder/_formio-component-file.scss
new file mode 100644
index 0000000000..0f92ec6d54
--- /dev/null
+++ b/src/openforms/scss/components/builder/_formio-component-file.scss
@@ -0,0 +1,6 @@
+.formio-component-file {
+  .list-group-item {
+    background-color: var(--body-bg);
+    border-color: var(--hairline-color);
+  }
+}
diff --git a/src/openforms/scss/components/builder/_index.scss b/src/openforms/scss/components/builder/_index.scss
index 1ba8b2ca34..fcdeaecab6 100644
--- a/src/openforms/scss/components/builder/_index.scss
+++ b/src/openforms/scss/components/builder/_index.scss
@@ -4,5 +4,8 @@
 // fixes of styling broken by django admin styling
 @import 'formio-component-checkbox';
 
+// Fix for dark theme
+@import 'formio-component-file';
+
 @import 'columns';
 @import 'openforms-component';
diff --git a/src/openforms/scss/components/builder/_openforms-component.scss b/src/openforms/scss/components/builder/_openforms-component.scss
index e87522eb2d..84feee4c79 100644
--- a/src/openforms/scss/components/builder/_openforms-component.scss
+++ b/src/openforms/scss/components/builder/_openforms-component.scss
@@ -1,3 +1,5 @@
+@import '~microscope-sass/lib/typography';
+
 @import '../../../ui/static/ui/scss/settings';
 @import '../../vars';
 
@@ -14,6 +16,10 @@
       $color-tooltip-background 20px
     );
 
+    legend {
+      @include h2(auto);
+    }
+
     label {
       color: $color_dark;
     }
@@ -22,4 +28,12 @@
       opacity: 0.9;
     }
   }
+
+  .ck-editor__main {
+    // TODO: Formio uses CKEditor5, but using their dark theme seems more complex than for the tinymce.
+    // So for now we keep the default theme, but ensure that the text in the editor is dark and not light.
+    @media (prefers-color-scheme: dark) {
+      color: $color-dark;
+    }
+  }
 }