the false-color hubble pictures are narrowband pictures, taken with the 3 common narrowband filters which pick up the red light from 1) the hydrogen-alpha transition, 2) the sulfur-2 transition (also red) and 3) the oxygen-iii transition (kind of a blue-green color) because SII and Ha would be the same color to the human eye (if we could see them – extremely deep red), SII is mapped to the red channel, Ha to green, and OIII to blue.

if you could see that galaxy with your own eyes, it would look very much like the picture above.

source: i am myself an amateur astrophotographer.

most serious astrophotographs are taken with black and white cameras with the above-mentioned filters in front of the sensor. each filter is exposed separately for several hours, but cut up into 5-10 minute exposures and stacked. then the channels are combined to RGB images. when you use RGB filters, you see what the eye would see.