I've already done something similar with a gemma, (2) 8mm neopixels and a
HC-SR505 PIR sensor on a rather ... ah hem .. popular articulating dragon model. I haven't posted the make, yet.
Yeah, I can think of some encoding fun particularly on the dimming, but didn't think of adjusting the rgb values. I'll have or add a bank of a few button presets to make sure I can always return back. For fun, I was thinking of different programs for Christmas twinkling, audio level gauges, message indicator through flashing, phone call notifier, door bell?, who knows, lots of ideas.