Template for Creating Chromium-based Web Browser Theme

Template repository for customizing your browsing experience by designing your unique Chromium-based web browser theme from scratch.

Tip

⭐ Star This Repository

If you find this theme template and my work useful, please consider supporting me giving a ⭐ star ⭐ to this repository, and follow me on GitHub.

List of Chromium-based Web Browsers

Browser	Tested	Theme Supported	Browser Developer
Google Chrome	✅	✅	Google
Microsoft Edge	✅	✅	Microsoft
Ungoogle Chromium	✅	✅	Slimjet
Vivaldi	🔴	☑️	Vivaldi Technologies
Opera	🔴	☑️	Opera Software
Brave	🔴	☑️	Brave Software

• ✅ Tested/Supported

• ☑️ Should work in theory

• 🔴 Not Tested

Note

This theme uses Manifest V3 to ensure compatibility with the latest Chromium extension standards.

A sample of the manifest.json file containing all supported properties.

{
  "author": "I am Programmer <[email protected]>",
  "description": "Chrome theme by I am Programmer",
  "icons": {
    "128": "image/store_icon_128x128.png"
  },
  "manifest_version": 3,
  "name": "Simple Theme",
  "short_name": "simple_theme",
  "theme": {
    "colors": {
      "control_background": [0, 0, 0],
      "control_button_background": [0, 0, 0],
      "background_tab": [0, 0, 0],
      "background_tab_inactive": [0, 0, 0],
      "background_tab_incognito": [0, 0, 0],
      "background_tab_incognito_inactive": [0, 0, 0],
      "bookmark_text": [0, 0, 0],
      "button_background": [0, 0, 0],
      "frame": [0, 0, 0],
      "frame_inactive": [0, 0, 0],
      "frame_incognito": [0, 0, 0],
      "frame_incognito_inactive": [0, 0, 0],
      "ntp_background": [0, 0, 0],
      "ntp_header": [0, 0, 0],
      "ntp_link": [0, 0, 0],
      "ntp_link_underline": [0, 0, 0],
      "ntp_text": [0, 0, 0],
      "ntp_section": [0, 0, 0],
      "ntp_section_link": [0, 0, 0],
      "ntp_section_link_underline": [0, 0, 0],
      "ntp_section_text": [0, 0, 0],
      "omnibox_background": [0, 0, 0],
      "omnibox_text": [0, 0, 0],
      "tab_background_text": [0, 0, 0],
      "tab_background_text_inactive": [0, 0, 0],
      "tab_background_text_incognito": [0, 0, 0],
      "tab_background_text_incognito_inactive": [0, 0, 0],
      "tab_text": [0, 0, 0],
      "toolbar": [0, 0, 0],
      "toolbar_button_icon": [0, 0, 0],
      "toolbar_text": [0, 0, 0]
    },
    "images": {
      "theme_frame": "images/theme_frame.png",
      "theme_frame_inactive": "images/theme_frame_inactive.png",
      "theme_frame_incognito": "images/theme_frame_incognito.png",
      "theme_frame_incognito_inactive": "images/theme_frame_incognito_inactive.png",
      "theme_frame_overlay": "images/theme_frame_overlay.png",
      "theme_frame_overlay_inactive": "images/theme_frame_overlay_inactive.png",
      "theme_toolbar": "images/theme_toolbar.png",
      "theme_ntp_background": "images/theme_ntp_background.png",
      "theme_tab_background": "image/theme_tab_background.png",
      "theme_tab_background_incognito": "images/theme_tab_background_incognito.png",
      "theme_tab_background_inactive": "images/theme_tab_background_inactive.png",
      "theme_tab_background_incognito_inactive": "images/theme_tab_background_incognito_inactive.png",
      "theme_ntp_attribution": "images/theme_ntp_attribution.png",
      "theme_button_background": "images/theme_button_background.png",
      "theme_window_control_background": "images/theme_window_control_background.png"
    },
    "tints": {
      "background_tab": [0, 0, 0],
      "buttons": [0, 0, 0],
      "frame": [0, 0, 0],
      "frame_inactive": [0, 0, 0],
      "frame_incognito": [0, 0, 0],
      "frame_incognito_inactive": [0, 0, 0]
    },
    "properties": {
      "ntp_background_alignment": "bottom",
      "ntp_background_repeat": "repeat",
      "ntp_logo_alternate": 1
    }
  },
  "version": "1.0.0",
  "version_name": "simple_theme_v1.0.0"
}

Important

Chromium has discontinued the use of "ntp_section," but it still utilizes it as a fallback option for "ntp_header" in order to support legacy themes.

{
 "theme": {
   "colors": {
     "ntp_section": [0, 0, 0],
   }
 }
}

Please remove all unused properties from the manifest.json file. If you use images, make sure that the image file exists at the path and that the image dimensions are correct.

(back to top)

---

🧰 Resource

• The list of properties supported by the Chromium browser has been extracted from this source.

  • https://source.chromium.org/chromium/chromium/src/+/main:chrome/browser/themes/browser_theme_pack.cc

• Theme Creation Guide By Patrick Batenburg

  • https://github.com/Patrick-Batenburg/GoogleChromeThemeCreationGuide

(back to top)

---

💕 Credits

• I am Programmer @iamprogrammerlk

  iamprogrammer.lk 🔸 [email protected] 🔸 x.com/iamprogrammerlk 🔸 youtube.com/@iamprogrammerlk

• Contributors

(back to top)

---

✨ Get Involved

Get in touch with the project developers and the community through our GitHub Discussions forum. View contributing.md for information.

(back to top)

---

🔥 Issues

Bug reports and feature requests can be submitted on the Github Issues.

(back to top)

---

👍 Code of Conduct

This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Code of Conduct, Security Policy, and be bound by the terms of the Contributor License Agreement.

Important

This project is not a platform for discussing politics, social issues, race, religion, gender, or sexual orientation. Please keep those discussions elsewhere.

(back to top)

---

⚖️ License

This work is distributed under the MIT License License. See license for more information.

Permissions

• ✅ Commercial use
• ✅ Distribution
• ✅ Modification
• ⛔ Patent use
• ✅ Private use

Conditions

• ⛔ Disclose source
• ✅ License and copyright notice
• ⛔ Network use is distribution
• ⛔ Same license
• ⛔ State changes

Limitations

• 🚫 Liability
• ⛔ Trademark use
• 🚫 Warranty

(back to top)

---

©️ Copyright

• Copyright © 2025 🇱🇰 I am Programmer @iamprogrammerlk.
• Copyright © 2025 ❤️ Contributors.

(back to top)

---