Applying the Custom Background In-Game
After modifying the resource pack with your custom image, you must activate the pack within Minecraft's settings to view your new main menu background.
Enabling the Resource Pack
1. Launch Minecraft to reach the main menu.
2. Click on Options, then select Resource Packs.
3. In the Available Resource Packs list on the left, locate Custom Background HD.
4. Hover over the pack and click the arrow icon to move it to the Selected Resource Packs list on the right.
5. Click Done.
Verifying the Background
The game will reload its texture system, which may cause a brief loading screen. Once the reload finishes, return to the main title screen. The default background will now be replaced with your chosen HD image.
If the original background still appears, confirm that your custom image was saved as a .png file named panorama_overlay.png and placed directly inside assets/minecraft/textures/gui/title/background/ within the pack archive.