Why are fictional holograms and real-life prototype holograms blue-shaded?

Question

In Star Wars, the holograms they have are usually projected in blue, or are blue-tinted ((or in another solid color) but they also have fully colored, life-like holograms as seen in the clone wars and comics etc.) also, real life prototypes (however limited) seem to always have a blue tint. I'm just figuring that seeing as how they are lasers, they are in one color (the single laser being used). This makes sense because if you have a small, handheld projector, one laser/color is all that is necessary and it would cut down on size and cost (and blue holograms just look so cool haha). So if anyone knows much about hologram technology or laser-physics, I'd like to know a bit more about the science and concept behind holograms (especially the blue ones haha)

Answer 1

Not all of them

Answer 2

Can't answer for the fictional ones...they are, after all, fiction. The writers could have them that color for anything they can think of...like, its my wife's favorite color for example.



And totally disagree with your assertion about the real ones. You apparently have never done the haunted house at Disney World or Land. These houses are filled with holograms (as ghosts) and they are very varied in color and quite realistic. Check this out:



"Not many people realise that Hologram technology hasn't changed much since the birth of the idea. In fact, there is no such thing as a hologram that can be projected into thin air. Hmmm, that's not what we have been told right, well it's true. Holograms require the viewer to look through a piece of film. Holograms only create the illusion of a 3D object but that image is stored and only exists on a flat 2D surface just like a photograph." [See source.]

Answer 3

The "real" ones look like because that's what they look like in the movies. The other posters are right. Real holograms are not projected. Most of the things out there these days claiming to be holograms are really just using old OLD tricks, similar to reflections in a sheet of glass. By making a video that looks like a movie version of a hologram and reflecting it off a semi-transparent screen hidden onstage, they can create an illusion that looks similar to what we see in the movies, but still, it's just a flat 2D image. The Michael Jackson "hologram" did just that for example.

Answer 4

Haha, you're right never been to Disney world lol. And as for real-life holograms (thin air ones) technically they still don't exist, but many leading companies/scientists believe we are getting close. And my question (single laser color) was more based on the premise of future (conceptual) holograms. But thanks for the answer! And I wonder if George Lucas's wife's favorite color is blue haha