Using Selenized with OS X default terminal is problematic. That's because Terminal.app has a misfeature: it will modify the colors you set in preferences according to its own liking, and you cannot disable this behaviour.
Therefore I strongly recommend that Mac users switch to iTerm, which seems to be a much better terminal emulator anyway. You can find Selenized color palette for iTerm here.
Copy the values from here to Terminal.app's preferences. Remember to use coordinates from correct color space.