Today, two new themes have been added to ZFGC:
Goron Red
Zora Blue
They're both just color variants of the Kokiri Green theme, but people have been asking for blue & red for a while now, so <_<
You can select these themes by going to your Profile, going to Look & Layout preferences, then clicking the (change) link and selecting either the Goron Red or the Zora Blue themes from the list. Enjoy.
Edit: Also, yes, they do work on the portal because the portal draws from the user's forum theme, so