be03b35f ​

input = fill 5v (fill 5h black) |> fold (fold rect) #0
output = [[#1, #2], [blue, #3]]
(OList UList ((VInt, HInt, VInt, HInt), Color), Color, Color, Color)
([{((5v, 1h, 5v, 2h), blue), ((4v, 2h, 5v, 2h), blue), ((1v, 5h, 2v, 5h), blue), ((1v, 4h, 1v, 5h), blue), ((1v, 1h, 1v, 2h), blue), ((1v, 1h, 2v, 1h), blue), ((4v, 4h, 5v, 5h), red)}], blue, black, blue)
([{((4v, 1h, 5v, 2h), blue)}, {((1v, 4h, 1v, 5h), blue), ((1v, 4h, 2v, 4h), blue), ((2v, 1h, 2v, 2h), blue), ((1v, 1h, 2v, 1h), blue), ((5v, 1h, 5v, 1h), black), ((4v, 4h, 5v, 5h), red)}], black, blue, blue)
([{((5v, 1h, 5v, 2h), blue), ((4v, 4h, 5v, 5h), red), ((1v, 5h, 2v, 5h), blue), ((1v, 1h, 1v, 2h), blue)}], blue, black, black)
([{((5v, 1h, 5v, 2h), blue), ((4v, 1h, 5v, 1h), blue), ((2v, 4h, 2v, 5h), blue), ((1v, 5h, 2v, 5h), blue), ((1v, 2h, 2v, 2h), blue), ((1v, 1h, 1v, 2h), blue), ((4v, 4h, 5v, 5h), red)}], ?, ?, ?)