Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

Since upgrading to Docusaurus v3.10, the 🗃 (Card File Box) emoji on generated-index pages renders as a monochrome text style glyph instead of a colorful emoji.

Root cause seems to be getFallbackEmojiIcon in DocCard with only the category icon affected. Looks unintentional. This was introduced in #11734

Reproducible demo

No response

Steps to reproduce

1. Sidebar with type : 'category' and a link with type: 'generated-index' (and no custom emoji provided in label)

Expected behavior

The 🗃️ emoji renders in color emoji presentation, consistent with pre v3.10 behavior and with the other DocCard emojis (📄️, 🔗) in the same function.

Actual behavior

Renders as monochrome

Your environment

• Public source code:
• Public site URL:
• Docusaurus version used: 3.10
• Environment name and version (e.g. Chrome 89, Node.js 16.4): Any browser, Node 24
• Operating system and version (e.g. Ubuntu 20.04.2 LTS): W11 25H2

Self-service

• I'd be willing to fix this bug myself.