At the point of having more than 7-10 top-level lists, it starts to become difficult to navigate and differentiate them quickly. I have hacked this by using unicode character icons at the start of my lists, and the result has been very positive. I am able to navigate (and remember the purpose of) my lists much more efficiently. I suggest implementing a very simple version of this which would build the icon into the bullet and have a menu for selecting an appropriate one. My setup: https://www.dropbox.com/s/okwvy6jsml3yrpl/Screenshot%202016-04-10%2000.20.58.png?dl=0