I think depression can cause color perception loss (not complete, but colors fade out).
Also when getting used to a second or third language (i.e. french _ english) one can temporarily get overwhelmed and have difficulty to switch to either of them. I never came accross literature on this, but personaly experienced periods of a day or more where I felt I just couldn’t speak anything. Asking friends moving to foreign countries some of they hit the same issue.
At that time at least in France “specialist” would tell the most random diagnostics with a straight face and it was pretty normal to go get a second opinion for anything more than a cold. Nowadays they know patients have at least googled symptoms and try to ecplain more of their thinking behind diagnostics IMO.