Many years ago I (and Tom Sibley) proved that any tiling (finite or infinite) with Penrose rhombs is 3-colorable as a map (a question raised by John Conway). And later the same was proved for Kites and Darts. So I wonder if the same is true for hats. Ed: If you send me a pile of hats I can run my 3-coloring program on it. I even made a carpet showing 3-colored rhombs.