Print out the "Shell" and "Top" pieces as the color of the stone, then print the "Inner Block" as whatever other color you want.

Assemble by placing the Inner Block inside of the shell, then place the top on it.

Now you have a Minecraft ore block.

Print instructions

I printed this at 0.2 mm resolution at 5-10% infill.

When printing the shell, flip it upside down so that it is open on top.

This should require no supports.