Although the easy way to tell is when you look through them if they have a blueish tint they are Ruby, if they have a greenish yellowish tint they are Fire.
Like I said earlier, these replacement lens are much more yellow than my new, current release ruby Juliet's, night and day, no comparison. Other than the back of these lens I would swear they are fire! Guess that batch was baked w/fire...;P
I just saw both Ruby Pennys and Ruby Juliets at the San Francisco "O" Store. They both looks great, almost like the original batch expect there is no purple hues.