Betta turning grey with white underneath

Question
Hi. I've been looking online for answers to my question and the only one I found talked about the betta turning grey and how it was old age, but no one mentioned the white underneath his head.
I got the betta about 2 months ago. I have no idea where he came from (I won him in a contest....he was one of the last 2 bettas left...so he's my cute little reject betta). He was doing fine for a while (I think he's always had a little bit of grey on his face....it looks like the scales have just turned grey.) He had a white patch under his chin, too. It's not fuzzy and doesn't look at all like it would be a fungus. The grey is now extending from his head to his dorsal fin(?) (the one on top), and it looks like someone just drew a line form his head to his fin. the grey isn't on his sides or anything. Then on the bottom of his head, it's all grey.
He lives in a 1 gallon tank. It's not heated, and I apologise but I don't know any ammonia levels or anything like that.
I'm currently treating him for fin rot (I went away for a few days on vacation and came back to see about 1/2 an inch of his tail fin was shredded).
P.S. All of the grey/white stuff was there before the fin rot

Answer
Hello,
Fin, and Tail rot should be treated with a good antibiotic.  The grey could be that the betta is changing colour, this happens sometimes.  If you see any yellowish golden like dusting powder on his body, it could be velvet, in that case you would have to treat him for velvet.  As for the white spot, if it isn't fungus, and he is eating, I would not worry too much about it unless it got bigger.  Bettas need heated tanks, and should be in 5 gallons of water or more.  In their habitat, the betta's water may be shallow but they have lots of room to swim.  There water temperature should be 80 degrees. He is cold under this temperature.  When heating the betta's water it should be done very very slowly.  One degree every two days.   Bettas kept in small bowls, vases, etc. will get sick, and are very hard to cure in such little water.
Vary his diet, this is very important.  Feed him Betta Pellets one day, the next Betta Flakes, the next, Daphnia, the next glass worms, the next bloodworms etc.  The more your vary, the healthier he will be.  Feed him small amounts twice a day..example: two pellets for one meal.  The Betta's tummy is the size of his eye.  We must always remember this when feeding him.  Feed him one cooked frozen pea a week with the outer layer removed, and cut into tiny pieces.  This is to clean out his system, and avoid Swim Bladder Disease.
Make sure his water is very clean, free of ammonia, nitrites, and nitrates are low.  Ammonia is the number one killer of fish.
Hope this helps
Lynda