These mazes were designed an atypical way. By following a few basic ground rules (regarding the shape and size of the colour groups) it turns out that a remarkable number of grid arrangements naturally yield good mazes, requiring little or no refinement.

A key underlying reason for such a high yield is the relative ease of arranging the grid such that the resulting state-diagram is fully connected (all states are both reachable and escapable) despite also being a directed graph (where moves are non-reversible). This type of state-diagram is technically known as a strongly connected digraph which, perhaps not surprisingly, turns out to yield some very nice mazes.