Make the collapse/expand triangles look more like buttons

[Mathew_Georghiou]

I love the collapse/expand feature but I fear that many users will not realize that the black triangles are interactive, for two reasons:

1. They are very small
2. They are black

Adding a simple colored circle in behind would help (not just on rollover as it does now).

Or make them a hot color and larger.

Or do both.