diff --git a/translations/ar.json b/translations/ar.json
index 8c29f449b..b9e8d8cd2 100644
--- a/translations/ar.json
+++ b/translations/ar.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "نسخ ولصق في النص الخاص بك",
     "shrug": "هز كتفيه",
     "DM warning": "لا يتم تشفير الرسائل المباشرة من طرف إلى طرف. لا تشارك أي معلومات حساسة للغاية هنا.",
-    "Transcript": "نص"
+    "Transcript": "نص",
+    "Color contrast is too low": "تباين الألوان منخفض جدًا"
 }
diff --git a/translations/ca.json b/translations/ca.json
index a9c118186..1991807d4 100644
--- a/translations/ca.json
+++ b/translations/ca.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Copia i enganxa al teu text",
     "shrug": "arronsar les espatlles",
     "DM warning": "Els missatges directes no estan xifrats d'extrem a extrem. No compartiu cap informació molt sensible aquí.",
-    "Transcript": "Transcripció"
+    "Transcript": "Transcripció",
+    "Color contrast is too low": "El contrast de color és massa baix"
 }
diff --git a/translations/cy.json b/translations/cy.json
index b7f96b940..f99c7ed63 100644
--- a/translations/cy.json
+++ b/translations/cy.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Copïwch a gludwch i'ch testun",
     "shrug": "shrug",
     "DM warning": "Nid yw negeseuon uniongyrchol wedi'u hamgryptio o'r dechrau i'r diwedd. Peidiwch â rhannu unrhyw wybodaeth hynod sensitif yma.",
-    "Transcript": "Trawsgrifiad"
+    "Transcript": "Trawsgrifiad",
+    "Color contrast is too low": "Mae cyferbyniad lliw yn rhy isel"
 }
diff --git a/translations/de.json b/translations/de.json
index f57fd9646..e5b728fcd 100644
--- a/translations/de.json
+++ b/translations/de.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Kopieren und in Ihren Text einfügen",
     "shrug": "zucken",
     "DM warning": "Direktnachrichten sind nicht Ende-zu-Ende verschlüsselt. Geben Sie hier keine hochsensiblen Informationen weiter.",
-    "Transcript": "Abschrift"
+    "Transcript": "Abschrift",
+    "Color contrast is too low": "Der Farbkontrast ist zu gering"
 }
diff --git a/translations/el.json b/translations/el.json
index 2d7d326bf..9cdf972e9 100644
--- a/translations/el.json
+++ b/translations/el.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Αντιγράψτε και επικολλήστε στο κείμενό σας",
     "shrug": "σήκωμα των ώμων",
     "DM warning": "Τα άμεσα μηνύματα δεν είναι κρυπτογραφημένα από άκρο σε άκρο. Μην μοιράζεστε καμία εξαιρετικά ευαίσθητη πληροφορία εδώ.",
-    "Transcript": "Αντίγραφο"
+    "Transcript": "Αντίγραφο",
+    "Color contrast is too low": "Η χρωματική αντίθεση είναι πολύ χαμηλή"
 }
diff --git a/translations/en.json b/translations/en.json
index 5f220e82c..cce3649f1 100644
--- a/translations/en.json
+++ b/translations/en.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Copy and paste into your text",
     "shrug": "shrug",
     "DM warning": "Direct messages are not end-to-end encrypted. Do not share any highly sensitive information here.",
-    "Transcript": "Transcript"
+    "Transcript": "Transcript",
+    "Color contrast is too low": "Color contrast is too low"
 }
diff --git a/translations/es.json b/translations/es.json
index 5dcf0de6a..6007430d8 100644
--- a/translations/es.json
+++ b/translations/es.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Copia y pega en tu texto",
     "shrug": "encogimiento de hombros",
     "DM warning": "Los mensajes directos no están cifrados de extremo a extremo. No comparta ninguna información altamente confidencial aquí.",
-    "Transcript": "Transcripción"
+    "Transcript": "Transcripción",
+    "Color contrast is too low": "El contraste de color es demasiado bajo"
 }
diff --git a/translations/fr.json b/translations/fr.json
index 373cff572..7a471240a 100644
--- a/translations/fr.json
+++ b/translations/fr.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Copiez et collez dans votre texte",
     "shrug": "hausser les épaules",
     "DM warning": "Les messages directs ne sont pas chiffrés de bout en bout. Ne partagez aucune information hautement sensible ici.",
-    "Transcript": "Transcription"
+    "Transcript": "Transcription",
+    "Color contrast is too low": "Le contraste des couleurs est trop faible"
 }
diff --git a/translations/ga.json b/translations/ga.json
index 0094c1a4f..1a32a9b30 100644
--- a/translations/ga.json
+++ b/translations/ga.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Cóipeáil agus greamaigh isteach i do théacs",
     "shrug": "shrug",
     "DM warning": "Níl teachtaireachtaí díreacha criptithe ó cheann go ceann. Ná roinn aon fhaisnéis an-íogair anseo.",
-    "Transcript": "Athscríbhinn"
+    "Transcript": "Athscríbhinn",
+    "Color contrast is too low": "Tá codarsnacht dath ró-íseal"
 }
diff --git a/translations/hi.json b/translations/hi.json
index 2bb8a63cc..ae9141fd0 100644
--- a/translations/hi.json
+++ b/translations/hi.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "अपने टेक्स्ट में कॉपी और पेस्ट करें",
     "shrug": "कंधे उचकाने की क्रिया",
     "DM warning": "डायरेक्ट मैसेज एंड-टू-एंड एन्क्रिप्टेड नहीं होते हैं। यहां कोई अति संवेदनशील जानकारी साझा न करें।",
-    "Transcript": "प्रतिलिपि"
+    "Transcript": "प्रतिलिपि",
+    "Color contrast is too low": "रंग कंट्रास्ट बहुत कम है"
 }
diff --git a/translations/it.json b/translations/it.json
index ff7c18f9d..5dc4845ed 100644
--- a/translations/it.json
+++ b/translations/it.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Copia e incolla nel tuo testo",
     "shrug": "scrollare le spalle",
     "DM warning": "I messaggi diretti non sono crittografati end-to-end. Non condividere qui alcuna informazione altamente sensibile.",
-    "Transcript": "Trascrizione"
+    "Transcript": "Trascrizione",
+    "Color contrast is too low": "Il contrasto del colore è troppo basso"
 }
diff --git a/translations/ja.json b/translations/ja.json
index 58a6dd600..6bb22327f 100644
--- a/translations/ja.json
+++ b/translations/ja.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "コピーしてテキストに貼り付けます",
     "shrug": "肩をすくめる",
     "DM warning": "ダイレクトメッセージはエンドツーエンドで暗号化されません。 ここでは機密性の高い情報を共有しないでください。",
-    "Transcript": "トランスクリプト"
+    "Transcript": "トランスクリプト",
+    "Color contrast is too low": "色のコントラストが低すぎる"
 }
diff --git a/translations/ko.json b/translations/ko.json
index a98f6466c..123c26f42 100644
--- a/translations/ko.json
+++ b/translations/ko.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "텍스트에 복사하여 붙여넣기",
     "shrug": "어깨를 으쓱하다",
     "DM warning": "다이렉트 메시지는 종단 간 암호화되지 않습니다. 여기에 매우 민감한 정보를 공유하지 마십시오.",
-    "Transcript": "성적 증명서"
+    "Transcript": "성적 증명서",
+    "Color contrast is too low": "색상 대비가 너무 낮습니다."
 }
diff --git a/translations/ku.json b/translations/ku.json
index 7a20c6695..71ef6f0b1 100644
--- a/translations/ku.json
+++ b/translations/ku.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Di nivîsa xwe de kopî bikin û bixin",
     "shrug": "şuştin",
     "DM warning": "Peyamên rasterast bi dawî-bi-dawî ne şîfrekirî ne. Li vir agahdariya pir hesas parve nekin.",
-    "Transcript": "Transcript"
+    "Transcript": "Transcript",
+    "Color contrast is too low": "Berevajî reng pir kêm e"
 }
diff --git a/translations/nl.json b/translations/nl.json
index f199ac29b..59f01d702 100644
--- a/translations/nl.json
+++ b/translations/nl.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Kopieer en plak in je tekst",
     "shrug": "schouderophalend",
     "DM warning": "Directe berichten zijn niet end-to-end versleuteld. Deel hier geen zeer gevoelige informatie.",
-    "Transcript": "Vertaling"
+    "Transcript": "Vertaling",
+    "Color contrast is too low": "Kleurcontrast is te laag"
 }
diff --git a/translations/oc.json b/translations/oc.json
index 14d6bc176..016cdbef9 100644
--- a/translations/oc.json
+++ b/translations/oc.json
@@ -549,5 +549,6 @@
     "Copy and paste into your text": "Copy and paste into your text",
     "shrug": "shrug",
     "DM warning": "Direct messages are not end-to-end encrypted. Do not share any highly sensitive information here.",
-    "Transcript": "Transcript"
+    "Transcript": "Transcript",
+    "Color contrast is too low": "Color contrast is too low"
 }
diff --git a/translations/pl.json b/translations/pl.json
index f0458db43..077dd11a0 100644
--- a/translations/pl.json
+++ b/translations/pl.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Skopiuj i wklej do swojego tekstu",
     "shrug": "wzruszać ramionami",
     "DM warning": "Wiadomości na czacie nie są szyfrowane metodą end-to-end. Nie udostępniaj tutaj żadnych wysoce wrażliwych informacji.",
-    "Transcript": "Transkrypcja"
+    "Transcript": "Transkrypcja",
+    "Color contrast is too low": "Kontrast kolorów jest zbyt niski"
 }
diff --git a/translations/pt.json b/translations/pt.json
index de71f4bd7..eb594d052 100644
--- a/translations/pt.json
+++ b/translations/pt.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Copie e cole no seu texto",
     "shrug": "dar de ombros",
     "DM warning": "As mensagens diretas não são criptografadas de ponta a ponta. Não compartilhe nenhuma informação altamente sensível aqui.",
-    "Transcript": "Transcrição"
+    "Transcript": "Transcrição",
+    "Color contrast is too low": "O contraste de cores é muito baixo"
 }
diff --git a/translations/ru.json b/translations/ru.json
index bbc9dd157..f82cc2c70 100644
--- a/translations/ru.json
+++ b/translations/ru.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Скопируйте и вставьте в свой текст",
     "shrug": "пожимание плечами",
     "DM warning": "Прямые сообщения не подвергаются сквозному шифрованию. Не делитесь здесь особо конфиденциальной информацией.",
-    "Transcript": "Стенограмма"
+    "Transcript": "Стенограмма",
+    "Color contrast is too low": "Цветовой контраст слишком низкий"
 }
diff --git a/translations/sw.json b/translations/sw.json
index faa5b24e0..4f8c99e2c 100644
--- a/translations/sw.json
+++ b/translations/sw.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Nakili na ubandike kwenye maandishi yako",
     "shrug": "piga mabega",
     "DM warning": "Ujumbe wa moja kwa moja haujasimbwa kutoka mwisho hadi mwisho. Usishiriki maelezo yoyote nyeti sana hapa.",
-    "Transcript": "Nakala"
+    "Transcript": "Nakala",
+    "Color contrast is too low": "Utofautishaji wa rangi uko chini sana"
 }
diff --git a/translations/tr.json b/translations/tr.json
index 80887499f..d1ab905da 100644
--- a/translations/tr.json
+++ b/translations/tr.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Metninize kopyalayıp yapıştırın",
     "shrug": "omuz silkmek",
     "DM warning": "Doğrudan mesajlar uçtan uca şifrelenmez. Son derece hassas bilgileri burada paylaşmayın.",
-    "Transcript": "Transcript"
+    "Transcript": "Transcript",
+    "Color contrast is too low": "Renk kontrastı çok düşük"
 }
diff --git a/translations/uk.json b/translations/uk.json
index 80b07c3c0..559788e5d 100644
--- a/translations/uk.json
+++ b/translations/uk.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "Скопіюйте та вставте у свій текст",
     "shrug": "знизати плечима",
     "DM warning": "Прямі повідомлення не наскрізне шифруються. Не публікуйте тут дуже конфіденційну інформацію.",
-    "Transcript": "Стенограма"
+    "Transcript": "Стенограма",
+    "Color contrast is too low": "Колірна контрастність надто низька"
 }
diff --git a/translations/yi.json b/translations/yi.json
index 563169306..afe00dbb5 100644
--- a/translations/yi.json
+++ b/translations/yi.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "קאָפּי און פּאַפּ אין דיין טעקסט",
     "shrug": "שעפּן זיך",
     "DM warning": "דירעקט אַרטיקלען זענען נישט ענקריפּטיד פון סוף צו סוף. דו זאלסט נישט טיילן קיין העכסט שפּירעוודיק אינפֿאָרמאַציע דאָ.",
-    "Transcript": "טראַנסקריפּט"
+    "Transcript": "טראַנסקריפּט",
+    "Color contrast is too low": "קאָליר קאַנטראַסט איז אויך נידעריק"
 }
diff --git a/translations/zh.json b/translations/zh.json
index d0c2c6f1e..b5db64510 100644
--- a/translations/zh.json
+++ b/translations/zh.json
@@ -553,5 +553,6 @@
     "Copy and paste into your text": "复制并粘贴到您的文本中",
     "shrug": "耸耸肩",
     "DM warning": "直接消息不是端到端加密的。 不要在这里分享任何高度敏感的信息。",
-    "Transcript": "成绩单"
+    "Transcript": "成绩单",
+    "Color contrast is too low": "颜色对比度太低"
 }
diff --git a/webapp_theme_designer.py b/webapp_theme_designer.py
index b88752b20..66ad9b3d4 100644
--- a/webapp_theme_designer.py
+++ b/webapp_theme_designer.py
@@ -223,6 +223,23 @@ def html_theme_designer(css_cache: {}, base_dir: str,
         'name="submitThemeDesigner" accesskey="' + submit_key + '">' + \
         translate['Submit'] + '</button>\n    </center>\n'
 
+    background = None
+    contrast_warning = ''
+    if theme_json.get('main-bg-color'):
+        background = theme_json['main-bg-color']
+        foreground = None
+        if theme_json.get('main-fg-color'):
+            foreground = theme_json['main-fg-color']
+            contrast = color_contrast(background, foreground)
+            if contrast:
+                if contrast < 4.5:
+                    contrast_warning = '⚠️ '
+                    theme_form += \
+                        '    <p><label class="labels">' + \
+                        contrast_warning + '<b>' + \
+                        translate['Color contrast is too low'] + \
+                        '</b></label></p>\n'
+
     table_str = '    <table class="accesskeys">\n'
     table_str += '      <colgroup>\n'
     table_str += '        <col span="1" class="accesskeys-left">\n'
@@ -238,9 +255,14 @@ def html_theme_designer(css_cache: {}, base_dir: str,
         if 'font-size' in variable_name:
             variable_name_str = variable_name.replace('-', ' ')
             variable_name_str = variable_name_str.title()
+            variable_name_label = variable_name_str
+            if contrast_warning:
+                if variable_name == 'main-bg-color' or \
+                   variable_name == 'main-fg-color':
+                    variable_name_label = contrast_warning + variable_name_str
             font_str += \
                 '      <tr><td><label class="labels">' + \
-                variable_name_str + '</label></td>'
+                variable_name_label + '</label></td>'
             font_str += \
                 '<td><input type="text" name="themeSetting_' + \
                 variable_name + '" value="' + str(value) + \