Far too often in scientific publications, the choice of colourmap for a figure has been given no thought. How do I know? Because every colour in the rainbow has been used.
For some reason rainbow colourmaps are the default in many programs, despite them being inappropriate for countless situations. I am not the first to recommend never using the rainbow/jet/hsv/etc… colourmaps, but apparently it needs repeating. If I arbritrarily pick a journal and go to the most recent articles, I am bound to come across multiple instances of these awful colour schemes.