NASA performs an enhancement of color based on the spectrum of light reaching them, which helps them understand the complexities of the celestial bodies they study. Yes, the actual image they see is black and white, but that’s also to catch finer details that a normal color photo might miss. The resulting color scheme seen in this photo, for example, wasn’t processed by the camera, but based on their measurements of the elements present and their resulting spectra based on a multitude of factors, including heat, dispersion, etc. Basically, they don’t color them so they look pretty, (although I think that is a plus in lieu of bland photos); they color them to understand better what they’re observing. Read more about it here.
True Colors of Pluto
Source: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Alex Parker
Published: July 23, 2018
This is the most accurate natural color images of Pluto taken by NASA’s New Horizons spacecraft in 2015.