Instant Insanity / Buvos Golyok

'Instant Insanity' consists of four separate cubes. Each side of a cubehas a single colour. There are four colours. The aim of the puzzle is to put thecubes on top of one another in a tower such that each side is a mix of all fourcolours. The colours of the other faces (hidden inside the tower or top/bottom) donot matter.It is often incorrectly thought that each side of the tower should haveonly one colour. This is impossible on all versions I have seen.The second picture shows a Hungarian version (Buvos Golyok) which uses a frame containing ballswith spots on them instead of separate cubes.The puzzle became popular in the 1960's when it was produced by Parker Brothers,but it is actually much older. It was first made around 1900 and was then called'The Great Tantalizer'. More recently it has also been sold as Cube-4, or Trikki 4.As far as I know, most four cube versions of the puzzle that have been producedare essentially the same. They nearly all have the following cubes, though possi...