Color coding of arrows based on level of nesting and open/closed state

The arrows of folders in the sidebar are great. But they are hard to tell apart when the nesting structure gets deep and numerous.

1st suggestion:
Have some sort of color coding based on the level of nesting. the top level folder might be red. a folder in that folder might have an orange arrow. a level 3 folder may have a yellow arrow, and so on, repeating back at red for nesting beyond 6 or 7.

2nd suggestion: have the "right arrow" and "down arrow" be visually different. They would be more visually distinct. They aren't that hard to tell apart currently, but I think it would ease visual distinction a lot. For instance, leave the right arrow as is. Have the down arrow be be hollow - just a gray border of a triangle while the inside of the triangle is transparent.