Zen LEDs displaying a rainbow of colors

What causes the Zen LEDs to display a rainbow of colors and what does it mean?

I finally figured out today that the 10-foot USB extension cable I was using was causing my new Zen (“Grand 200 block”) to persistently report an AQI of around 150, with LEDs glowing bright red. I first registered it on December 28th and it has been connected to WiFi and showing as the only red station on the Purple Air map for miles around since then.

The only way I can rationalize it is that the extension cable had enough of a voltage drop to cause a falsely high AQI “floor” (instead of 0) because the LEDs were glowing bright red and the Zen was connected to WiFi just fine.

So today by process of elimination I figured out the cable was the culprit (along with what I presume is a weird Zen design flaw) and it’s now finally showing single-digit AQIs consistent with other outdoor sensors nearby.

So now everything seems fine after replacing the 10-foot extension cable with 2 6-foot cables I had lying around … however for a long time (I gave up waiting after climbing a ladder and taking the attached photo) the LEDs were constantly cycling through all colors of the rainbow. What did / does that mean? Is it design intent?

[https://photos.app.goo.gl/DHhd4zbBLZ5xzTz37](https://Zen LEDs flashing a rainbow of colors)