I can't tell you because I wasn't looking over the shoulder of whoever made the image, but at a guess they started off from a black and white image, then turned it into an RGB image and change the various hues until relevant details became easier to see. The reason that that works is because a large scale structure has areas that emit at roughly the same intensity so you can bring these out by colorizing such a range with a gradient around a single hue.
This is not an automated process because a computer would not know what we humans find 'interesting structures', if you could put that into some form of definition then you might be able to automate the process in the same way that black-and-white images are automatically colorized (which works, but which is sometimes hilariously wrong).
As for the sausage, how it is made is interesting, how it tastes is from a PR perspective probably more interesting. And regardless you could argue that anything that differs from an utterly black square is 'not truthful'.
I can't tell you because I wasn't looking over the shoulder of whoever made the image, but at a guess they started off from a black and white image, then turned it into an RGB image and change the various hues until relevant details became easier to see. The reason that that works is because a large scale structure has areas that emit at roughly the same intensity so you can bring these out by colorizing such a range with a gradient around a single hue.
This is not an automated process because a computer would not know what we humans find 'interesting structures', if you could put that into some form of definition then you might be able to automate the process in the same way that black-and-white images are automatically colorized (which works, but which is sometimes hilariously wrong).
As for the sausage, how it is made is interesting, how it tastes is from a PR perspective probably more interesting. And regardless you could argue that anything that differs from an utterly black square is 'not truthful'.