Autumn Alpine route timing

I understand there's a large range in autumn color change for the Tateyama Alpine route because of the elevation. I've read from late Sept to early Nov, so October in general is probably the best. I am wondering when in October is the best balance of good colors in the most scenic areas?

I'm not planning for this year, but considering a trip next fall. Another consideration is that we would likely try to do this and Kamikochi first, and then explore the rest of Nagano and Gifu prefectures. So I am wondering if starting the trip around Oct 14 or 21 might be better for example.

Late September will limit the colors to the Murodo area (and this year it may be too early for colors even then). So, I suggest mid October when the range of colors is likely to be largest.