You could make the normal color of the logo a bright flickering of orange-yellow ◼◼◼◼, which gradually fades to a dark red ◼ as the battery goes down, with pulses of bright red ◼ if it gets critically low. Bluetooth activity could be flashes of sky blue ◼ and network activity could be flashes of purple for download ◼ and cyan ◼ for upload. The left SD slot could be blue ◼ and the right one could be green ◼. Incoming messages could be indicated with pulses of white ◻, at a rate of k Hz if you've got k new messages.
Controllable RGB leds are nice.
No offence regarding your ideas and creativity, but I don't want a device that looks like it came from a christmas lights designer on an LSD trip ^_^
That's a bit overkill... yes
But as it's userspace, it's up to the user what he wants to do.
The powerswitch will have an RGB LED as well, so the button could be green for a full battery and fade via yellow, orange into a red.
So you could always see the battery status if you like.