An image of Sagittarius A*, the black hole in the center of the Milky Way galaxy, has just been published. This is only the second such feat. The first image was of the central black hole of the galaxy M87. The images were captured through the collaboration of 8 synchronized radio telescopes around the world called The Event Horizon Telescope. It is an impressive technical problem to solve. Seeing something the apparent size of the M87 black hole as viewed from earth is said to be like trying to see a bagel on the surface of the moon. And they did it with sub-millimeter radio waves.
The color of the objects is interesting. I wonder how many folks out there think that radio telescopes can record the visual color of an object?
Lamentations on Chemistry 
Define “color”
From Wikipedia- Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra.
In ordinary use I think that color refers to that electromagnetic radiation which we can detect with our eyes. It’s tempting to use the word when describing bands of radiation across the whole spectrum, but I’ll decline to go there.
Thanks, gaussling. I’m with you. Color is what you can see. Otherwise why would we have the word “colorblind”?
OK, there are apparently some bugs and some birds who can see farther into the UV than you or I so we can cut them some slack and broaden their definition of color.