Recently upgraded from the ISY994i to the EISY with the dongle.  It came with two antennae marked with color coded rings.  It took me some time to find out which went where so I felt if I posted it it would be easier for people to find if they had the same question.  The answer I received was that yellow=Z-Wave and red=Zigbee.  Other than that the upgrade was as simple as backing up the config from the ISY and restoring it to the EISY.  

There should have been a sheet if instructions included in the envelope. I know there was back when it was first being shipped out. But, you're right...if not in there it's difficult to find.

There was a link available to them when the product was released and first shipped for the ZMatter board that referenced the colors. It's still in the wiki, but I think only under the Polisy entry and more for the internal board for the Polisy.

https://www.universal-devices.com/docs/ZMatter-Assembly- Instructions.pdf

 

I just received my dongle as well - no instructions in the box, but found the answer in this post - nice to have an active user community!

 

Yellow = Z-Wave

Red = Zigbee