Hello, is there any easy way / tutorial, how to make “block” of liquid? For example like sube 1x1x1, but with liquid effect and to be able to change color of that liquid.

Yes. Make a cube, then make a liquid material, and put that material on the cube. the cube will be solid, but look like liquid. Making a liquid material is tricky if you dont know material creation techniques. You can buy or get for free water materials and replace the color nodes with a parameter…