Its possibly an issue with the specific colour-blind accessibility option. I'm not color blind, so I went to check if applying the setting if the Tritanopia does show them as being 2 different colours - for me red bars were red and the Nightmare was the pinkish colour. You may want to see if Deuteranopia or Protanopia provide better results for you depending on why you have it on, if none of them are suitable you'll likely need to post over on feedback about them expanding the color blind mode options to allow for individual changes