5 · Multiply two safe tables

Pick the two factors. The product keeps outer colors between rooms and gives each room fresh inner colors, and this page re-checks every triangle of the result, live.

Try this. Multiply the sixteen table by itself: 256 people, 6 colors, zero bad triangles out of 2.7 million checked. Then look at the rate: it never beats the better factor.

The drawing shows rooms and the strings between them faintly; the verdict below is computed from the full product, every triple.