The problem is that such a system is actually more easy to game and have a larger proportion of voters not support the overall policy. If 51% of districts are

The problem is that such a system is actually more easy to game and have a larger proportion of voters not support the overall policy. If 51% of districts are 51% yellow while 49% are 100% pink, yellow wins. With a second level, you can run that game twice, and 25% are enough to win.