Codex Blue Selection

A lightweight text selection highlighter for Chrome and Microsoft Edge. It replaces the browser's default selection color with a soft Codex-style blue while keeping websites clean and unchanged.

Keywords: Chrome extension, Edge extension, text selection, selection highlight, blue highlighter, browser customization, Codex blue.

Features

• Soft blue text selection on webpages, inputs, textareas, and editable content.
• Automatic light/dark webpage detection with separate color presets.
• Custom light and dark selection colors with live preview.
• Global enablement with an exact per-site toggle.
• Immediate updates across open tabs and iframes without refreshing.
• Local-only settings, no analytics, no network requests, and no selected-text collection.

Install

From a GitHub release

1. Download the latest Codex-Blue-v1.1.0.zip from Releases.
2. Extract the ZIP file.
3. Open chrome://extensions/ or edge://extensions/.
4. Enable Developer mode.
5. Choose Load unpacked and select the folder containing manifest.json.

From source

Clone this repository and load its root directory as an unpacked extension. No build step or runtime dependency is required.

Privacy

Codex Blue Selection stores its color preferences and disabled-site list in chrome.storage.local. It does not transmit data, track browsing activity, read selected text, or include remote code.

Development

npm test
npm run check
npm run serve

The local test page covers light and dark themes, inputs, editable text, long content, author-defined selection styles, and iframes.

Browser limitations

• Browser settings pages, new-tab pages, extension stores, and built-in PDF viewers block content scripts.
• Closed Shadow DOM selection styles cannot be overridden.
• Transparent page backgrounds fall back to the operating system theme.

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中文说明

Codex Blue Selection 是一款适用于 Chrome 和 Microsoft Edge 的轻量划词美化扩展，只做一件事：把网页默认文字选区替换成柔和、清晰的 Codex 风淡蓝色。

功能

• 支持普通文字、输入框、文本域和可编辑区域。
• 自动识别网页深浅背景，分别使用浅色与深色选区方案。
• 支持自定义两套选区颜色并实时预览。
• 默认全站启用，可按精确网站域名单独关闭。
• 设置即时同步到已打开的网页和 iframe，无需刷新。
• 设置只保存在本机，不联网、不统计、不读取划词内容。

本地安装

1. 从 Releases 下载 Codex-Blue-v1.1.0.zip 并解压。
2. 打开 chrome://extensions/ 或 edge://extensions/。
3. 开启“开发者模式”。
4. 点击“加载已解压的扩展程序”，选择包含 manifest.json 的目录。

许可证

MIT