The feature you are looking for is primarily available through the resource pack, created by CrisXolt . This UI pack replaces standard static interface elements with a dynamic, multi-colored (Chroma) animation across various screens in Minecraft. Key Features of Animated RGB GUI

: Requires OptiFine or the Animatica mod (for Fabric) to function correctly.

: The animations are typically designed with 40 frames , resulting in a very smooth "wave" effect that moves across the UI. Cross-Platform Support :

: Beyond just the HUD, it includes animated RGB colors for the Hotbar , XP Bar , and nearly all inventory container screens, including anvils, beacons, brewing stands, and chests.