@thisisartman @APoD it means the colors are as close to as possible to what a human eye would see.

Many astronomy images are colored in ways that make the scientifically interesting features stand out, often even with arbitrarily chosen colors, instead of trying to show what we'd actually see with our own eyes. Especially with distant objects they would be so faint to our eyes anyway that we would not see them clearly or detect any color at all.

The first released photos of Pluto made it appear much more red than this.