99306f82 ​

input = fill #0 (fill #1 black) |> rect (#2, blue) |> fold rect #3
output = fill #0 (fill #1 black) |> fold (fold rect) #4
(VInt, HInt, (VInt, HInt, VInt, HInt), UList ((VInt, HInt, VInt, HInt), Color), OList UList ((VInt, HInt, VInt, HInt), Color))
(10v, 10h, (3v, 3h, 8v, 8h), {((1v, 1h, 1v, 1h), green), ((2v, 2h, 2v, 2h), red), ((4v, 4h, 7v, 7h), black)}, [{((3v, 3h, 8v, 8h), blue)}, {((4v, 4h, 7v, 7h), green)}, {((1v, 1h, 1v, 1h), green), ((2v, 2h, 2v, 2h), red), ((5v, 5h, 6v, 6h), red)}])
(15v, 15h, (4v, 4h, 12v, 12h), {((1v, 1h, 1v, 1h), red), ((3v, 3h, 3v, 3h), yellow), ((2v, 2h, 2v, 2h), fuschia), ((5v, 5h, 11v, 11h), black)}, [{((4v, 4h, 12v, 12h), blue)}, {((5v, 5h, 11v, 11h), red)}, {((6v, 6h, 10v, 10h), fuschia)}, {((1v, 1h, 1v, 1h), red), ((3v, 3h, 3v, 3h), yellow), ((2v, 2h, 2v, 2h), fuschia), ((7v, 7h, 9v, 9h), yellow)}])
(15v, 15h, (5v, 5h, 14v, 14h), {((1v, 1h, 1v, 1h), teal), ((4v, 4h, 4v, 4h), red), ((3v, 3h, 3v, 3h), yellow), ((2v, 2h, 2v, 2h), fuschia), ((6v, 6h, 13v, 13h), black)}, [{((5v, 5h, 14v, 14h), blue)}, {((6v, 6h, 13v, 13h), teal)}, {((7v, 7h, 12v, 12h), fuschia)}, {((8v, 8h, 11v, 11h), yellow)}, {((1v, 1h, 1v, 1h), teal), ((4v, 4h, 4v, 4h), red), ((3v, 3h, 3v, 3h), yellow), ((2v, 2h, 2v, 2h), fuschia), ((9v, 9h, 10v, 10h), red)}])
(20v, 20h, (6v, 6h, 18v, 19h), {((1v, 1h, 1v, 1h), red), ((5v, 5h, 5v, 5h), orange), ((4v, 4h, 4v, 4h), teal), ((3v, 3h, 3v, 3h), brown), ((2v, 2h, 2v, 2h), green), ((7v, 7h, 17v, 18h), black)}, ?)