These diagrams are produced by colouring each trigram – albeit rather arbitrarily. The combination of colours creates new visual effects.
Here the hexagrams change from 00 to 77, i.e. Earth to Heaven, starting in the four different outer corners of a matrix 1, 2, 3, 4:
And now in reverse order 4, 3, 2, 1: starting in the inner corners, 77 changes into 00, while Heaven turns into Earth.