FOSS gamedev and creative worlds

I read around searched google, I just can't seem to get the greyscale textures to work. I had them working once but Idk how. any help would be great. Also if this is in the section I apologize feel to free to move it.

Are you creating grayscale textures? On which surfaces, nodes, items, entities, meshes?

Are those actual optimized 8-bit textures or just 24-bit textures that happen to have only grayscale colors?

Ok was on my phone earlier was a little hard to type lol.

Anyway I am trying to use a 24bit greyscale image for the grass_top and all tree leaves at one time they worked, no they are just showing as grey in game as well.