I tend to agree that color would be good with some caveats:
Rare modal color change usage can be powerful. e.g red = problem
The more colors there are the more confusing it can be when switching interfaces from say Now Bubbles to Devices (where gray = OFF, for example)
Perhaps the basic reason there aren’t colors (yet) is because complexity mounts quickly when all considerations are made. This is the norm for most of what Sense has to deal with so I credit them with keeping this visually pleasing and direct in the meantime.