This issue has already been solved. It will be in the update included on Sunday 7th January.
You can update in advance, but it may be best to wait if you’re not familiar with the command line.
You’ll need to add echo 1 > /sys/class/amhdmitx/amhdmitx0/output_rgb to /etc/rc.local. In the future, we’ll make a GUI option available.
Sam