I am always baffled by the new ideas I still get from other people games after years of gaming...the "one color dice" per character is brilliant!
Even if I must say that we usually roll once at a time, so it's not so needed to distinguish results, but surely is useful for the "where's my lucky 20?" things!
One question: how did you get your players to manage their preferences? As far as dice are concerned, I have all kinds of players, the one using the metal ones, the one liking pink-and-purple and so on...you get what I mean, I'm sure.
As per the initiative cards, apart from the bloat of cards reducing tension, which I already said a lot about so not repeating, I fear that colors are worse than images for inspiration sake.
Once again...it will work for sure, only a little bit less intriguing, I think.