c074846d ​

input = fill #0 (fill #1 black) |> rect ((#2, #3, #2, #3), grey) |> rect (#4, red)
output = fill #0 (fill #1 black) |> fold (λr. rect ((#6, r.2, #5, r.2), r.1)) #7 |> fold (λr. rect ((#8, r.2, #9, r.3), r.1)) #10
(VInt, HInt, VInt, HInt, (VInt, HInt, VInt, HInt), VInt, VInt, UList (Color, HInt), VInt, VInt, UList (Color, HInt, HInt))
(5v, 7h, 3v, 4h, (3v, 2h, 3v, 3h), 2v, 1v, {(red, 4h)}, 3v, 3v, {(grey, 4h, 4h), (green, 2h, 3h)})
(6v, 7h, 4v, 5h, (4v, 2h, 4v, 4h), 3v, 1v, {(red, 5h)}, 4v, 4v, {(grey, 5h, 5h), (green, 2h, 4h)})
(7v, 7h, 4v, 4h, (3v, 4h, 3v, 4h), 4v, 4v, {(red, 5h), (grey, 4h)}, 3v, 3v, {(green, 4h, 4h)})
(3v, 3h, 2v, 2h, (2v, 3h, 2v, 3h), 3v, 3v, {(black, 3h), (red, 2h)}, 2v, 2v, {(green, 3h, 3h), (grey, 2h, 2h)})
(7v, 7h, 5v, 5h, (6v, 5h, 7v, 5h), 7v, 6v, {(green, 5h)}, 5v, 5v, {(grey, 5h, 5h), (red, 3h, 4h)})
(9v, 9h, 6v, 4h, (7v, 4h, 9v, 4h), ?, ?, ?, ?, ?, ?)
(9v, 11h, 5v, 6h, (1v, 6h, 4v, 6h), ?, ?, ?, ?, ?, ?)