Like many others who have posted in this thread, I struggled a fair amount in the new trial because of the devs insistence on making an orange marker overlay on a red floor. I didn't struggle as much in M5 seeing as the ground is a much more muted color of red so seeing the markers for where the attacks were gonna hit wasn't too much of an issue, but there were times where I exploded from otherwise avoidable damage, especially during the later parts of the fight.
I regularly use colorblind accessibility settings in other games for the comfort of my own eyesight seeing as I am nearsighted and rely on glasses in order to see, but as the patches go on and the fights get more visually intense, I start to worry.
I shouldn't have to sacrifice my own eyesight just to play a game that I enjoy.