Feeling like the world is colorless if having colours go dull, can be a sign of depression.
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Furball, I understand what you mean by that symptom and yeah it is trippy, I've had it once before I had a POTS collapse. At the time I was somewhere where I couldnt lay down when I felt the POTS coming on and needed to lay (and wasnt allowed to go home when I needed to), then the world went all trippy in its colours, more vivid and not only that, like the world went more spacy too (and echoy a bit too), my distance perception went a bit trippy too. I then went to stand up (as I was forced to do so as I was being called into court.. so this whole thing was a stress situation too) and ended up fainting after about 2 steps, came to on the floor after, several minutes later ?? all shaking still (like a seizure incident), I just came properly consciousness just before the ambulance people arrived but I still couldnt sit up even 15 mins later without more symptoms coming in again.
This was all caused by my POTS and lack of blood getting to my brain with maybe intense stress being involved on top of that (I havent had colours alter like that before my other POTS collapses). People had rang an ambulance and as I was told I couldnt stay laying on the floor, the ambulance officers carried me out to my boyfriends car. (one of the ambulance officers on that occassion actually understood POTS, so didnt insist on me having to go to hospital).
anyway.. I see my experience as what is called an "aura" which can happen right before a migraine or seizure, so take care if you are getting this symptom (do not try to drive).