Block Outline Customizer

A client-side Minecraft mod that lets you fully customize the block selection outline. Available for Fabric and NeoForge.

Features

• Custom colors — RGB sliders for the outline and an optional translucent fill
• Outline styles — Full, Dashed, or Corner brackets
• Width & opacity — outline width from 1 to 10, fully adjustable opacity
• Rainbow mode — animated RGB cycling with adjustable speed, optionally synced between outline and fill
• Custom RGB palette — pick exactly which colors the RGB effect cycles through (empty = full rainbow)
• Corner gradient — RGB can flow spatially across the block starting from its corner instead of one uniform color
• Moving dashes — the dashed style can march along the edges with adjustable speed
• Pulse — breathing opacity animation
• Presets — built-in looks (Classic, Neon, Subtle, Rainbow) plus a savable Custom slot
• Per-block overrides — give specific blocks or block tags their own style (e.g. highlight #c:ores in gold), editable in the config file
• In-game config screen with live preview — press U (rebindable) while aiming at a block and watch the real outline update as you drag the sliders; opened from ModMenu (Fabric) / the mod list Config button (NeoForge) it shows a grass block preview instead
• Custom look — dark card UI with tabbed sections, RGB gradient sliders, color swatch, and a hex color field

Configuration

Everything can be changed from the in-game screen. The config file is shared by both loaders and lives at config/blockoutlinecustomizer.json.

Per-block overrides

Overrides are edited in the config file. Each entry matches block ids or #-prefixed block tags and applies its own complete style:

"blockOverrides": [
  {
    "name": "Ores",
    "enabled": true,
    "blocks": ["#c:ores", "minecraft:ancient_debris"],
    "style": {
      "outlineRed": 255,
      "outlineGreen": 170,
      "outlineBlue": 0,
      "outlineWidth": 3.0
    }
  }
]

Unspecified style fields use their defaults. The first matching override wins.

Building

./gradlew build

Jars are produced in Fabric/build/libs and NeoForge/build/libs. Requires Java 25 (Gradle downloads a toolchain automatically).

License

MIT