c658a4bd ​

input = fill #0 (fill #1 black) |> fold (fold rect) #2
output = fill #3 (fill #4 #5) |> fold (fold rect) #6
(VInt, HInt, OList UList ((VInt, HInt, VInt, HInt), Color), VInt, HInt, Color, OList UList ((VInt, HInt, VInt, HInt), Color))
(13v, 13h, [{((2v, 1h, 7v, 6h), teal)}, {((3v, 2h, 6v, 5h), black)}, {((5v, 4h, 12v, 11h), red)}, {((6v, 5h, 11v, 10h), black)}, {((2v, 9h, 5v, 12h), green), ((6v, 5h, 7v, 6h), teal)}, {((10v, 1h, 11v, 2h), yellow), ((6v, 5h, 6v, 5h), black), ((3v, 10h, 4v, 11h), black)}], 8v, 8h, red, [{((2v, 2h, 7v, 7h), teal)}, {((3v, 3h, 6v, 6h), green)}, {((4v, 4h, 5v, 5h), yellow)}])
(16v, 16h, [{((8v, 2h, 14v, 8h), teal)}, {((9v, 3h, 13v, 7h), black)}, {((10v, 6h, 16v, 14h), green)}, {((11v, 7h, 16v, 13h), black)}, {((11v, 7h, 14v, 8h), teal), ((3v, 11h, 5v, 13h), blue), ((2v, 4h, 6v, 8h), yellow)}, {((3v, 1h, 3v, 1h), red), ((11v, 7h, 13v, 7h), black), ((4v, 12h, 4v, 12h), black), ((3v, 5h, 5v, 7h), black)}], 9v, 9h, green, [{((2v, 2h, 8v, 8h), teal)}, {((3v, 3h, 7v, 7h), yellow)}, {((4v, 4h, 6v, 6h), blue)}, {((5v, 5h, 5v, 5h), red)}])
(19v, 19h, [{((2v, 3h, 11v, 12h), fuschia)}, {((3v, 4h, 10v, 11h), black)}, {((6v, 6h, 13v, 13h), green)}, {((7v, 7h, 11v, 12h), fuschia)}, {((7v, 7h, 10v, 11h), black)}, {((4v, 5h, 9v, 10h), teal)}, {((15v, 12h, 18v, 15h), yellow), ((6v, 6h, 8v, 9h), green)}, {((3v, 16h, 4v, 17h), red), ((16v, 13h, 17v, 14h), black), ((12v, 7h, 12v, 12h), black), ((7v, 7h, 8v, 9h), black), ((5v, 6h, 5v, 9h), black)}], ?, ?, ?, ?)