Probably has to do with enhanced color via filters. They look pretty real to me but we’re used to seeing objects filtered for hydrogen and other wavelengths.
They are all “fake” ie ... digitally enhanced. I actually got to meet the guy from NASA that does this. the pictures they get from deep space are really binary translations of infrared images from cameras from the 60’s... so they make educated guesses about some of the colors. Also, he said any photography in deep space is tricky because there is so little light and nothing for the flash to bounce off of...