Yeah so maybe both Neptune and Uranus look hazy and dull green in visible light. So what?! They're both entire worlds, significantly larger and vastly different in climate and tilt and composition and weather phenomena than our own, and we're lucky enough to have seen them up close with probes. They have layered structure that can be seen in other wavelengths (e.g. infrared) and so many mysteries we haven't yet conceived. Plus a ton of moons each that are weird and fascinating in their own right. They're not the least bit boring to a curious mind.
Serious answer: the sensors in telescopes and probes don't work exactly like human eyes. They pick up a different range of frequencies than our cone cells in the first place, and don't have the same sort of overlapping input curves. There's a lot of tricks and techniques in converting an image into the same sort of thing we'd see with the naked eye. You can sorta think of it like translating Japanese into English; there's no perfect formula and it requires some creative interpretation no matter what.
The popular images that get published all over are simplistic composites and never really reflect the actual data astronomers rely on, so that was never a hindrance to scientific progress. It suddenly made the news because a research group decided to reevaluate the old data and reinterpret it against calibrations from other equipment (e.g. Voyager probe vs. the Very Large Telescope here on Earth). There's a general interest factor in "wow that looks so much different than the old pictures", when the underlying data really hasn't changed.
To add to this, we apparently always knew. The famous blue image is more or less the correct hue, but the saturation has been absolutely blown out like a clickbait youtube thumbnail in order to show faint features more clearly. Somewhere along the line we stopped mentioning that that had been done. Irwin and co just just re-calculated it to get the most accurate version yet, because we've got a lot more data to work with now than we did back when Voyager 2 did its fly-by
Furthermore, it's not that the original scientists failed to produce true-color images. The original published images of Neptune had deliberately enhanced colors to better show some of the features of the cloud surface, and the description text of the images said as much. But that nuance was quickly forgotten and everybody just took the deep blue coloring to reflect the actual color of the planet, which spread to depictions of the planet everywhere.
As the white/gold versus blue/black dress debate showed, our perception of color is heavily influenced by context, and is more than just a simple algorithm of which rods and cone cells were activated while viewing an image.
Nasa is ruining every planet one-by-one. First pluto wasn't a planet. Then neptune is even more boring and stupid than previously thought. Next thing we know, Mars isn't a planet anymore because planets aren't red.
Technically the concept of a planet is a social construct. Scientists have been scurrying around redefining the definition of a planet to exclude asteroids ever since they discovered them. Why can't they just say that the Earth is a wet asteroid and be done with it?
A hell-sphere that would be easier to fix than Mars, which is an entirely different type of hell-sphere. Just toss in enough ice to make eventual oceans and some cyanobacteria, and it should calm down in a few hundred thousand years.
Short of an artificial black hole at its center to raise the gravity, I don't see how we could ever terraform Mars. There's not enough gravity for anything that evolved here to be healthy there.