I went through Peter's "Kolor Killers" and tried out the routine. I would like to say that this is an excellent routine and another excellent approach to Roy Walton's Oil and Queens plot. I really love the ending climax and each of the phases. The reason is because the nature of this routine itself I can see will fry the spectators many times in the process with the great impact. A well-constructed routine.
To be honest, the first time I watched Peter's performance at his site, firstly I thought and I told myself "I think Peter is going to separate the colors of the cards and I am sure at the end, he will produce the Queens." - But I am wrong, he produced the Kings, Queens and the big excitement for me is, the Queens have the cross at the back of the cards! And another bonus is that, the "cross" patter fits in nicely with the climax. I think this routine is flexible too, you can change your patter to suit your preference.
Perhaps instead you use red-backed cards, you may use blue backed as a substitution and at the end, perhaps you change your patter to the "Queens turn angry" and at the end, you produce the red-backed Queens. Anything is possible.
Another question I asked myself "Hey, so, what happened to those spot cards then?" This is where my curiosity comes in, and I am surprised that the method is simple.
Perhaps you would like to check out Peter's "Laughing Queens" in his 7 ebook, another great version too.
Perhaps I am a little biased as I favor Walton's Oil and Queens plot. As you can see, when I watch a magic show or clip, I always put my position as a layman perspective and based on my thoughts, I am sure this routine would play very well to laymen.