Autopalette

Autopalette is a client-side modification for Minecraft based on Forge that uses a resource loader to create color variations of existing textures directly during the loading of game resources. This mod does not require installation on the server and is completely useless when installed on the server side.

When installed on the client, Autopalette activates the ability to load special JSON files that generate textures with modified color palettes when resource packs are loaded or reloaded. It's important to note that the created textures do not replace the originals and can be used alongside them.

Detailed information about creating JSON files for automatic texture generation is available in the documentation on GitHub.

Also on GitHub, you can find an example mod that uses Autopalette to create the dark cobblestone texture shown above.