I have Hyperion running on a Rpi3.
I upgraded from alpha.7 this morning and with no HDMI input I get a rainbow effect. I've disconnected the HDMI leads and the USB from the capture device to ensure it's no a rogue signal.
Changing the background effect options has no effect. Neither does disabling the background effect when idle.
I can only get the LEDs off by manually using the Remote Control - Components Control panel.
In all other respects it's working great, and thank you to all of the developers for time and effort.
I'm new to this so it's probably just an obvious setting I'm missing.