Long time lurker, first time poster - nice to meet you all!
Regarding red and gold: just stumbled on this WoB from the Nov 18th signing:
To me this explains the red (there's clearly some co-opting of magic going on) and just leaves gold.
Slight OB spoiler:
If I'm right, this has the most interesting implications for what happens in SA Book 5 (seeing as it's set before MB Era 2)