What limited entertainment there is to be had from a puzzle is directly correlated to how challenging it is. Five hundred pieces forming a bowl of fruit still life makes for a pleasant afternoon challenge, but a thousand pieces tinted a thousand different colors that assemble to create a CMYK color spectrum is just cruel and unusual punishment.
But there might be a few graphic designers out there with a couple hundred hours to spare willing to tackle the 1000 Colours (it's made in Australia) puzzle. It's one those rare cases where the picture on the box really isn't going to help you much. Instead, a fundamental understanding of color theory is far more useful here, as well as the patience of a saint. [1000 Colours via Boing Boing]