I have created a small texture pack that replaces the main Minecraft textures with the orange/dark gray default developer textures from Source. What do you think? I'm a small creator.
Just go to %appdata%, .minecraft folder, resourcepacks folder and there you go. It may say that it is for an older version. Ignore it, it works fine. THIS PACK IS FOR 1.16.1.
The leaves and grass keeps their green tint, unfortunely. However other blocks should work fine.
By the way, I accidentally also added a texture to the redstone torch. Hope it isn't annoying.