Might Have Been A Problem With Internal Reflection. - Blog Posts

This is a picture of the hydrogen and dust cloud surrounding the star Sadr (the bright white dot near the center) also known as IC 1318. The bright parts represent hydrogen clouds and the dark parts dust clouds. Those types of clouds are the birthplace of new stars. This particular photo is in black and white because it was made by using a filter that lets only the light emitted by ionised hydrogen (the H alpha spectral line) pass through it. This increases the visibility of the hydrogen clouds. Since this light is at 656 nm, it would appear bright red if coloured. Together with H beta (496 nm) also from hydrogen and O III (around 500 nm) from oxygen both cyan in color, they represent the majority of light emitted by gas clouds. So in conclusion if you were able to see this gas cloud directly it would appear a reddish-magenta color (H alpha being the dominant emission).