Is there a safe distance in which a black hole can be observed with the human eye? What is a safe distance?
I have seen many computer simulated and artist renditions, and I am not sure if they depicted the true colors and shape of BH.
Below I have a few of examples of what may a BH may look like rendered.
How light from the accretion disk maybe refracted by gravitational lensing. http://www.physics.utah.edu/~bromley/blackhole/index.html
Should these models be mixed to make a more complete rendition of a BH?