Astronomers View the Universe through Spectra Colored Glass
The top 10 elements in abundance in the Universe are:
Hydrogen, Helium, Oxygen, Neon, Nitrogen, Carbon, Silicon, Magnesium, Iron and Sulfur. The most abundant compound in the Universe is H20 Water. Hydroxyl OH is also highly abundant. Oxides of the top ten elements also have high abundance. When illuminated by Ultra Violet light, all elements and compounds emit unique spectra. Stars emit UV and hence the Universe can be analyzed by the spectral signatures of the materials in space. Spectra range from radio wavelengths to UV.
Studies of the Stars and nebulae often are done in the spectra wavelengths most affected by these elements and compounds.
Emission nebulae emit spectra of ionized elements and compounds. We view them through carefully designed filters that pass the particular group of wavelengths that they emit to study their motions and distribution of the materials. We can measure red and blue shifts in the wavelengths for material moving away or towards us respectively. Cool or shadowed materials will absorb those spectra rather than emit and produce dark lines in a spectrometer. Supernovae are rich with heavy elements and leave behind colorful remnants.
Hubble Space Telescope is a black and white camera with emission line filters aboard for seeking out these materials.
There are no Red, Green or Blue colored glass filters at all, just emission line filters that have no single color. To create a colored picture with Hubble data, astronomers assign different filters arbitrary colors. So we are coloring the distribution of elements and compounds. Naturally colored images are only done by Amateur Astronomers as those pictures have little Science value. While aesthetic, they lack specific data on the distribution and motions of materials in space. Professional Astronomers seek understanding the distribution and movements of materials in space. The amateur astronomer seeks beauty and the awesomeness of natural colored images.