I like the Olive color scheme the most, however, there is one thing missing from it that makes it very difficult to use. With the other schemes, I can read a post in threaded mode, and afterwards, scroll down to exactly where that post is located within the thread--as it's title differs slightly in color. With the Olive color scheme, the title's color is the same as those of the surrounding posts, so it makes it difficult to find. It seems as though perhaps a minor change would make this my favorite scheme on the board.
Obscurum per Obscurius: Ignotum per Ignotius.