d47aa2ff ​

input = fill 10v (fill 21h black) |> fold rect #0
output = fill 10v (fill 10h black) |> fold (λr. rect ((r.2, r.3, r.2, r.3), r.1)) #1
(UList ((VInt, HInt, VInt, HInt), Color), UList (Color, VInt, HInt))
({((1v, 11h, 10v, 11h), grey), ((9v, 19h, 9v, 19h), fuschia), ((9v, 13h, 9v, 13h), green), ((9v, 8h, 9v, 8h), fuschia), ((9v, 2h, 9v, 2h), green), ((7v, 18h, 7v, 18h), green), ((6v, 7h, 6v, 7h), green), ((5v, 15h, 5v, 15h), fuschia), ((5v, 4h, 5v, 4h), fuschia), ((3v, 17h, 3v, 17h), green), ((3v, 14h, 3v, 14h), green), ((3v, 6h, 3v, 6h), green), ((3v, 3h, 3v, 3h), green), ((2v, 20h, 2v, 20h), fuschia), ((2v, 9h, 2v, 9h), fuschia)}, {(fuschia, 9v, 8h), (green, 9v, 2h), (blue, 7v, 7h), (red, 6v, 7h), (fuschia, 5v, 4h), (green, 3v, 6h), (green, 3v, 3h), (fuschia, 2v, 9h)})
({((1v, 15h, 1v, 15h), yellow), ((1v, 11h, 10v, 11h), grey), ((1v, 4h, 1v, 4h), yellow), ((9v, 8h, 9v, 8h), brown), ((8v, 18h, 8v, 18h), brown), ((8v, 15h, 8v, 15h), teal), ((8v, 4h, 8v, 4h), teal), ((6v, 13h, 6v, 13h), yellow), ((6v, 2h, 6v, 2h), yellow), ((5v, 19h, 5v, 19h), yellow), ((5v, 8h, 5v, 8h), yellow), ((4v, 16h, 4v, 16h), teal), ((4v, 13h, 4v, 13h), brown), ((4v, 6h, 4v, 6h), teal), ((4v, 2h, 4v, 2h), brown), ((2v, 18h, 2v, 18h), teal), ((2v, 7h, 2v, 7h), teal)}, {(yellow, 1v, 4h), (red, 9v, 8h), (blue, 8v, 7h), (teal, 8v, 4h), (yellow, 6v, 2h), (yellow, 5v, 8h), (red, 4v, 6h), (blue, 4v, 5h), (brown, 4v, 2h), (teal, 2v, 7h)})
({((4v, 21h, 4v, 21h), green), ((1v, 11h, 10v, 11h), grey), ((9v, 15h, 9v, 15h), teal), ((9v, 8h, 9v, 8h), fuschia), ((9v, 4h, 9v, 4h), teal), ((7v, 19h, 7v, 19h), fuschia), ((6v, 15h, 6v, 15h), fuschia), ((6v, 4h, 6v, 4h), fuschia), ((5v, 6h, 5v, 6h), green), ((4v, 18h, 4v, 18h), green), ((4v, 13h, 4v, 13h), green), ((4v, 10h, 4v, 10h), green), ((4v, 2h, 4v, 2h), green), ((3v, 15h, 3v, 15h), teal), ((3v, 4h, 3v, 4h), teal), ((2v, 19h, 2v, 19h), teal), ((2v, 8h, 2v, 8h), teal)}, {(green, 4v, 10h), (red, 9v, 8h), (teal, 9v, 4h), (blue, 7v, 8h), (fuschia, 6v, 4h), (red, 5v, 6h), (blue, 4v, 7h), (green, 4v, 2h), (teal, 3v, 4h), (teal, 2v, 8h)})
({((10v, 13h, 10v, 13h), brown), ((10v, 2h, 10v, 2h), brown), ((1v, 11h, 10v, 11h), grey), ((1v, 5h, 1v, 5h), yellow), ((9v, 19h, 9v, 19h), yellow), ((9v, 16h, 9v, 16h), orange), ((9v, 8h, 9v, 8h), yellow), ((9v, 5h, 9v, 5h), orange), ((7v, 13h, 7v, 13h), yellow), ((7v, 2h, 7v, 2h), yellow), ((6v, 17h, 6v, 17h), orange), ((5v, 15h, 5v, 15h), brown), ((5v, 7h, 5v, 7h), orange), ((5v, 4h, 5v, 4h), brown), ((3v, 19h, 3v, 19h), brown), ((3v, 15h, 3v, 15h), yellow), ((3v, 8h, 3v, 8h), brown), ((3v, 4h, 3v, 4h), yellow), ((2v, 18h, 2v, 18h), yellow), ((2v, 13h, 2v, 13h), brown), ((2v, 2h, 2v, 2h), brown)}, ?)