User blog comment:--MULLIGANACEOUS--/Valentine's Day 2019: Massive nerfage!/@comment-25239866-20190219155724/@comment-26388711-20190220104355

I am the one who hid the 2-colored and 3-colored levels on episode pages because they were once rare. But it turned out that three-colored levels now appear (sometimes multiple times) in higher episodes, starting from around Level 2500, and four-colored levels are dominant in high episodes. Six-colored levels already become incredibly rare from L2500 and beyond, with frequency comparable to the early three-colored levels.

There is a clear trend that the average number of colors go down as you move further north. It is ironic that how these levels become so much harder.