I wish the green "Used/Free" bars showed usage instead of free space. I have to consciously interpret them every time I look at them. It sees like it would make more sense to show usage, so that they get higher as the disk fills up. The existing metaphor is akin to a gas tank—but in the case of a gas tank, full is what you want. Most interfaces for disk usage that I've seen indicate it in the sense of usage, where full is NOT what you want.

 

Further, the green bars don't aren't proportional—a full bar on a 1TB drive is the same size and length as the one on a 10TB drive, so they don't really give you any idea of actual free space on quick examination. If they were to show how close a disk is to being full (and turn red when close) they'd be more useful (to me, at least). 

 

As if to support this point, on the Dashboard, all the bars under Processor and System are "good" when they're low, and "bad" (red) when they're high.

 

Just my opinion, but I would be interested to hear yours.

You can change the color scheme.

 

Someone on Reddit showed me how to do it:

 

settings>display settings>used/free columns>select "Bar (color) - text">apply

Basically make sure you have "bar-text" and not "text-bar" set. This inverts the way the bars are displayed.

 

 

Text - Bar (color) looks like this:

 

Bar (color) - Text looks like this: