I searched the internet and found years worth of old threads talking about mcpatcher, the unfavorable optifine and more. The solution was simple: A quick custom pack made with the FabricSkyboxes mod, which adds its own pack format and comes with a detailed documentation and multi-purpose templates!
Installing Fabric Skyboxes
- Install latest Fabric: Fabric | The home of the Fabric mod development toolchain.
- Download Fabric API Fabric API – Minecraft Mod
- Download Fabric Skyboxes FabricSkyboxes – Minecraft Mod (MC 1.16 and above)
- Put both mods in .minecraft/mods (Alongside any other mods like Sodium, Iris, anything else)
- Run the Fabric profile installation from the Minecraft Launcher.
The FSB Skybox mod has come a long way – just check the first release post on Reddit 4 years ago.
Making your Skybox pack
Simply download your preferred template from the FSB Skybox docs and customize the files with help from the documentation (or YouTube depending on your specific needs)! There is an Examples and Templates heading at the bottom right: Specification | FabricSkyBoxes
To make your pack compatible with the correct version of Minecraft, put the correct pack version number in pack.mcmeta (Just edit the file with notepad): Pack format – Minecraft Wiki
Download Pure Blue Sky
DOWNLOAD: Pure Blue Sky (Fabric/FSB Skybox) Any Version Minecraft Texture Pack
INSTALLING: Put it in Resource Packs and run a Fabric Skybox installation of Minecraft. The pack version is currently 1.20-21. Unzip and change the Pack format to make it fully compatible with (hopefully) any ver.
HOW I MADE IT: For a Pure Blue Sky, I downloaded the first monochrome template, and set a custom color number in the texture files using RGB 0-1 Color Picker (rgbcolorpicker.com). I also set sun, moon and stars to false in the same text file to get a pure sky. (You might have to disable clouds/fog in-game.)