I bought this at an unmanned roadside stall, and there was no name. It was just four or five bright orange leaves big at that time in early May. It has now grown to be at least 75cm high and wide and the leaves are turning a darker red (though there is still some orange present). I think it's an annual plant that won't survive the winter (at least not in the Dutch climate) as the rest of the stall was filled with things like petunia, fuchsia, and lobelia, which also don't survive winters here.
I really like it and would like to be able to buy one next year, even if that same roadside shop doesn't offer one. So what is this called?