Ruby Iridium has a neutral base that tends to appear bluish when you look through them as they interact with the "red" mirror/iridium coating. Prizm Ruby has a bronze contrast base tint. The Prizm make certain colors pop more and gives a brighter feel as you look through them. If you have ever worn old school Gold Iridium lenses its kinda like that looking through...but not as good, and not as versatile in my opinion. Ruby Iridium is more like your traditional sunglasses lens, it darkens things up and lets you see a more normal color spectrum.
As for the mirror, Ruby has always been a crap shoot. Sometimes they look more yellow to orange than red. Sometimes they are very red with a deep purple center. Both Prizm and regular Iridium suffer from inconsistency in color. I have a pair of Prizm Ruby in Juliets that are very nice, but still have a lot of yellow "fire" look to the edges, but the reds and purples come through. Then I have a pair of Romeos with what we here call "fruby" Iridium lenses (rubies that look more like fire). Then I have 2 sets of Juliet Ruby Iridium that are the old school deep red with purple centers.
Prizm Ruby - a really lucky set. These to me are in between Ruby and Fruby. I haven't seen many Prizm Rubies with this good of a color to be honest.