Default Greek Fonts in OS X

[plethon]

OS X's built–in Polytonic Greek input is wonderful, but I have a question about how it switches default fonts.

In most sans–serif fonts, it uses Lucida Grande for Greek text when you switch input, and most serif fonts use Times. However, I prefer using another Greek font for serif text, and was wondering how this default font is selected.

In Pages, unlike TextEdit, this font switch doesn't even effect your base selection for English input, so I can begin a document in Hoefler Text, switch input—resulting in Times being used—then switch back input and still be using Hoefler Text. What I would like is for another font—such as Aristocoj or Porson—to be there, rather than Times.