There are quite a few other ways to train for unexpected tactical situations, here are a few:
1) Use of the actual firearm carried by yourself with an adapter to fire those Simunition rounds, and some really enthusiastic role players. This is pretty darned effective at dealing with unexpected situations. Note anything using Simunition requires proper protective gear, as does any type of shooting, but the gear is different for this type of shooting.
2) Use of shoot don't shoot targets that pop up or turn and face - or even ones already in place but which you approach from around a corner and only get to see once you clear the corner, or targets that are in the distance and you have to approach rapidly and shoot as appropriate. There are targets out there for instance that show a person holding a shotgun pointed at you, and then a sort of duplicate target that shows the exact same depiction except with that person holding an umbrella pointed at you just like the shotgun. This system is an amazingly good training system if you get the shooter's blood pumping first, either with a short run or an agility course, then have him/her enter the shoot/don't shoot area. It is amazing, even when you know this target is out there, how many times a person will shoot it once they have been pumped up and have already had to shoot a few other targets.
3) Another fairly fun shoot for this type of training is - darn I forget what you call it - but you are in essence shooting at a movie screen or big screen TV with movies of shoot/don't shoot scenarios. Once you shoot, it stops the action, and you can see if you connected, or even if you should have fired. Think it is called FATS...
One thing to remember about Cirillos method with the color system is that it gives you a cue that is not always there in a firefight. It has someone yelling out your targets to you. That would be akin to my yelling "brown shirt with a gun" to my partner(s) in a real life situation (and am I right about that, does that guy really have a gun). While this may happen, it is certainly not always the case, and may never be the case in any situation in which you find yourself. You also need to be ready to act or react on your own without someone telling you which are the threatening targets - you have to choose yourself.
Color code training is good at getting you to make some decisions regarding shoot/don't shoot sinceyou still have to decide if there is a blue target or not, or how many there are, or if you can hit it when it is behind the red target, when your instructor yells out blue. And it is good at getting your reflexes tuned. Yet I think it is lacking over a training system where there are less cues from an instructor/partner as when to shoot and more cues from the target on which you must base your decision. I feel it better to use a variety of shoot/don't shoot training systems to get you ready for the unexpected, just to keep it on the safer side.
Since I indicate that a color coded training/shooting system can have some drawbacks, I guess I should point out one of them. As silly as this next may seem, it could very likely hold water, especially with someone under a lot of stress:
Imagine if you will (thanks Rod Serling) that you are out on the streets and get a call about a really bad perp wearing a bright red shirt; he just killed a cop and wounded his partner and you get a 10-13 call. You are fired up by this. Then when you arrive at the scene after a five minute car ride at about 100 mph, you have to scale an eight foot wall to get into a dark alley. You are now really pumped up as you scan the alley for this puke. You hear noises at the end of the alley around the corner. You are pumping out adrenaline like no tomorrow. You get to the end of the alley, and you peek around to see a guy in a bright red shirt walking away - looking hinky at 4AM in that dimly lit alley and pretty much fitting the description of the bad guy in most or all regards. You have your handgun out, and you command him in a loud voice "Police don't' move". He just about poops his pants as he turns to face you holding a candy bar, or a television, or his penis because he had been peeing - or maybe even NOTHING - but it is dark and his hands are at about hip level, and coming up. Do you fire? What does your mind ask itself at that moment before you decide to fire, or does your mind ask anything at all since it has already seen enough? The decision you would make, would it be right decision? Remember you are making it in real life!
Of course here in this forum you already knew this was a setup, and knew it would be a tough situation, didn't you? The thing is though, I will make it tougher. You had been at the range the day before, and the range officer yelled red more than a few times, and you fired each time he did it. Heck everytime you go to the range the range officer uses this color code thing. It has become second nature for you to fire when the correct color is called out regardless of what color is being used as the threatening color (in other words it could be red, blue, green, yellow, white, etc...). This has been your training in the academy and at the range for the past year, two years, five years, ten years, twenty years! You never got into a really bad situation like this before. Are you sure you would have made the right decision under the above circumstances when you saw that red shirt? Are you sure that the color coding training would not have affected how you would have reacted to a visual cue, that being the red shirt or color coded target?
Now add just a little thing more to the scene to make it tougher yet, add a partner. Your partner sees the bad guy first. The partner does not yell "Police, don't move" but instead he yells to you "Red shirt, we got the red shirt". The same thing results, the suspect turns at you with hands coming up from about hip level. It is dark, it is 4AM, this guy fits the description of the perp pretty much, and you just heard your partner yell "Red...". Did you even hear the rest of it as all your attention now focuses on finding the "'red' threat? What would you do? Has the suspect already been shot by you when you realize his hands were empty, and that he only had been putting them up in surrender to show you that they were empty? Are you really sure you would make the correct decision after your partner had given you the verbal cue beginning with the word or containing the word "Red...", and then your having seen the visual cue of the red shirt? Would that color coded training have kicked i? If you did shoot, yes maybe you would have been found justified; but also maybe not. If you killed this guy, and it wound up being even just a homeless bum (whoops did I say bum), or maybe the trash collector, or maybe a kid, and not the actual bad guy: Could you really live with it if you realized you had shot the color?
I prefer more realistic training situations, but will admit that a color coded one can be helpful to a degree. I do think there is a better color coded system, and that is all red marked targets have guns (for when you cannot afford realistic shoot/don't soot targets). You approach these targets in the blind, and when you see red it means you are clear to fire. Yet this has some of the same drawback as the system above and it codes a color with a threat - be careful of the reactive type response this can trigger in you. I think the training should be more realistically based - the cue to shoot should not be a color but rather a weapon in hand or some other perceived threat that you believe you face from the subject. Even using inexpensive Air Soft type guns with marking pellets in a role player situation might be better training that the color coded one using real guns and ammo. Sure you are giving up using your actual weapon for this training, but you can always get lots of real fire training with your own gun at the range. If the basis for the training is how you react to a shoot/don't shoot situation - well you have to set your own priorities on that, and it may be better to make the situation more real to life as opposed to the gun being more real to life. Of course both being closer would be better, but they won't let us train on live volunteer targets with my issue weapon and live ammo...