In artistic renditions of space scenes, there were stunning depictions of gasses or galaxies with bold red and blue colors immediately adjacent to one another, in contact as water is with oil in a container. I wonder, are there known arrangements of gas like that, with both ends of the color spectrum adjacent to one another? If so, what are some examples, what is known about them, and what causes the two colors?
One reason I'd call it into question is that I'd imagine the properties of boldly blue gasses are different than those of red gasses. Maybe that assumption is wrong because the property of color isn't necessarily associated with other properties. Another assumption would be that gasses with very different properties wouldn't find themselves collecting adjacent to one another in space. That assumption could also be wrong - I'm not an astronomer and only have basic understanding of physics and chemistry.