So the Solar Castes have animal nicknames. The Dawns are Bronze Tigers, the Zeniths are Golden Bulls, the Twilights are Copper Spiders, the Nights are Iron Wolves, and the Eclipses are Quicksilver Falcons. When Castebook Dawn came out, it had Tiger Style in it. "Oh," said us on the forums. "I bet that means we'll get a new animal style in each of the castebooks, corresponding to the animal nicknames of the castes!"
That didn't happen.
So my answer remains, eternally, Bull Style, Spider Style, Wolf Style, and Falcon Style. That's been my answer to this question since 2001, and that will be my answer forever.