diff --git a/webapp/config.py b/webapp/config.py
index 86e92db..5f0076c 100644
--- a/webapp/config.py
+++ b/webapp/config.py
@@ -107,6 +107,11 @@ class Config:
     INSTANCE_SUBTITLE = _get(_instance, "instance", "subtitle", default="")
     INSTANCE_COPYRIGHT = _get(_instance, "instance", "copyright", default="")
 
+    # Theme colors (optional overrides from instance config)
+    THEME_PRIMARY = _get(_instance, "theme", "primary", default="")
+    THEME_PRIMARY_DARK = _get(_instance, "theme", "primary_dark", default="")
+    THEME_PRIMARY_LIGHT = _get(_instance, "theme", "primary_light", default="")
+
     # Telegram bot
     TELEGRAM_BOT_USERNAME = _get(_instance, "telegram", "bot_username", default="")
 
diff --git a/webapp/templates/base.html b/webapp/templates/base.html
index 9704828..5fca2f1 100644
--- a/webapp/templates/base.html
+++ b/webapp/templates/base.html
@@ -6,6 +6,15 @@
     <title>{% block title %}Data Analyst Portal{% endblock %}</title>
     <link rel="stylesheet" href="{{ static_url('style.css') }}">
     <link rel="stylesheet" href="{{ static_url('style-custom.css') }}">
+    {% if config.THEME_PRIMARY %}
+    <style>
+        :root {
+            --primary: {{ config.THEME_PRIMARY }};
+            {% if config.THEME_PRIMARY_DARK %}--primary-dark: {{ config.THEME_PRIMARY_DARK }};{% endif %}
+            {% if config.THEME_PRIMARY_LIGHT %}--primary-light: {{ config.THEME_PRIMARY_LIGHT }};{% endif %}
+        }
+    </style>
+    {% endif %}
 </head>
 <body>
     <div class="container">
diff --git a/webapp/templates/base_login.html b/webapp/templates/base_login.html
index 21e88e7..7eeae1f 100644
--- a/webapp/templates/base_login.html
+++ b/webapp/templates/base_login.html
@@ -6,6 +6,15 @@
     <title>{% block title %}Data Analyst Portal{% endblock %}</title>
     <link rel="stylesheet" href="{{ static_url('style.css') }}">
     <link rel="stylesheet" href="{{ static_url('style-custom.css') }}">
+    {% if config.THEME_PRIMARY %}
+    <style>
+        :root {
+            --primary: {{ config.THEME_PRIMARY }};
+            {% if config.THEME_PRIMARY_DARK %}--primary-dark: {{ config.THEME_PRIMARY_DARK }};{% endif %}
+            {% if config.THEME_PRIMARY_LIGHT %}--primary-light: {{ config.THEME_PRIMARY_LIGHT }};{% endif %}
+        }
+    </style>
+    {% endif %}
 </head>
 <body>
     {% with messages = get_flashed_messages(with_categories=true) %}
