• In Men in Black (1997), the neuralyzer devices employ a red flash. Red neuralyzer
  • A few years later, in Men in Black II (2002), the neuralyzers have apparently been upgraded or modified, and now use a blue flash.
  • In Men in Black III (2012), a 1969-time-travel scene shows a young Agent K using a neuralyzer powered by a belt-mounted battery pack.

Agent K originally retired at the end of Men in Black, during the age of red neuralyzers. Yet at the end of Men in Black II, K is shown activating a blue neuralyzer located in the torch of the Statue of Liberty, using his watch.

The implication seems very strong that this neuralyzer was K's secret, as it is activated by a watch which he kept in the locker, with the key hidden across town.

So how could the Statue's neuralyzer be blue? Wouldn't it be red, as that was the last "version" of neuralyzer he used before retiring in 1997?

  • 2
    Ehhh, just cause they were upgraded doesn't mean that one couldn't be upgraded with the remote trigger left alone. And just because it was a surprise to J, doesn't mean the rest of the agency didn't know about it
    – Tablemaker
    Dec 29, 2012 at 6:24
  • maybe he had a secret switch, and not the only switch. Maybe J was surprised because K remotely activated the neuralizer? J knew about it, but was surprised at K having a switch whole to himself. I think a neuralizer that size would have its controls at MIB HQ. Aug 15, 2013 at 15:58

3 Answers 3


I honestly wouldn't read too much into the color change matter, as the neuralizer itself is really a sort of MacGuffin. They aren't the main driving point of the movie like an actual MacGuffin, but they exist simply to provide an explanation to the question, "What about the people who witness aliens or the problems they cause while on Earth?".

We're never really told exactly how the neuralizers work (if I recall correctly), only that they're used to wipe the memories of anyone who has witnessed aliens that shouldn't have. As such, their existence in the movie is merely a simple solution to what would otherwise be a complex answer, and the color change between them could possibly just be a continuity error.


It is never implied in the movie whether the color of the neuralizers are any indication of their technological progress. You can simply put them as having different colors without reading too much into it.

There are many possibilities to your doubt, but I maintain that the colors were simply design choices, and nothing conscious. According to you, the mass neuralizer on the Statue of Liberty was blue. It could simply have been upgraded (if that is indeed the case) along with other neuralizer technology. It isn't shown that only K had the switch to activate the neuralizer. Maybe the MIB had a switch, and K personally had one? These details are not available in any canon. Hence, it will raise only opinions and speculations.

  • Good points. The color could simply be a personal preference of the user (sort of like a theme option), or it could be due to wherever they happened to be sourcing certain parts at the time of manufacture. Maybe they use crystals from different caves or something depending on which is cheaper when they need to make a new batch of neuralyzers. This could be like how Return of the Jedi makes us suspect that Luke's new green lightsaber is something new, but the prequels later reveal that green sabers aren't new - it's just that no one in Episodes IV-V happened to have one. Oct 15, 2016 at 0:52

I think since in the first movie the red one is not used on more than about 5 people at a time, but the blue ones in the 2nd and 3rd are used on about 40 people at once. The blue ones are for mass neuralization, while the red ones are basic shorter-range neuralizers.

  • As shown in the images, though, they're both being used within relatively close proximity to people.
    – MattD
    Oct 15, 2016 at 20:53

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