[mangamadaiyan]

> wondering if it's true to the human eye

Not really connected to your main question, but here goes -

The point is moot in the case of the Horsehead Nebula. The image is so dim (in the eyepiece of a telescope) that the human eye cannot perceive colour.

Also, it's a lot smaller in the eyepiece than most people expect - so it's pretty easy to miss.