Keep an eye on him for a few days. Fast him for 3-5 days and see if that does anything if in fact it is swim bladder disorder. Add epson salt if you would like. So far, it doesn't sound like he's particularly stressed. He's not palling in colour, hiding, ceased eating, or stopped interacting with you, so I wouldn't say he is sick just yet.
How much water did you change? When you do large abrupt changes sometimes they have difficulty adjusting their buoyancy. It has happened to my friend's betta couple of times, but he was able to readjust within a couple of hours.
I wouldn't personally be too concerned about the black scales on his head. The weird disfigured scales might point at something else though. In general, its common for a betta's colour to alter a bit throughout its lifetime. The body scales of your betta also show a bit of black in them! I think it's just an expression of the gene kicking in as he ages. My betta had his head turn from yellow to completely black. HIs body went from pale blue to deep blue. In a couple of months his face went orange and his body went back to the original colour. This is probably attributed to him having the marble gene in him. My red betta has a bit of black creeping on his body scales too as he's gotten older. You may also know that a lot of bettas have black heads, lacking "masks." Masks is a term used to describe a betta whose face colour is the same as the body. In the past, many bettas weren't bred to have masks and so their face colour is black. It's possible the expression for this gene is kicking in. Your betta is a veiltail and his genetic history is definitely a mystery since in this breed "anything goes". For all we know, his breeder intended him to be an extended red, but he may carry the red-wash gene or other genetic impurities that have lightened his colour with age and given rise to pigment spots. Pigment spots like yours are normal. It's particularly common in red bettas.
Bettas are comfortable with water even up to 84F so don't worry about him overheating.
How much water did you change? When you do large abrupt changes sometimes they have difficulty adjusting their buoyancy. It has happened to my friend's betta couple of times, but he was able to readjust within a couple of hours.
I wouldn't personally be too concerned about the black scales on his head. The weird disfigured scales might point at something else though. In general, its common for a betta's colour to alter a bit throughout its lifetime. The body scales of your betta also show a bit of black in them! I think it's just an expression of the gene kicking in as he ages. My betta had his head turn from yellow to completely black. HIs body went from pale blue to deep blue. In a couple of months his face went orange and his body went back to the original colour. This is probably attributed to him having the marble gene in him. My red betta has a bit of black creeping on his body scales too as he's gotten older. You may also know that a lot of bettas have black heads, lacking "masks." Masks is a term used to describe a betta whose face colour is the same as the body. In the past, many bettas weren't bred to have masks and so their face colour is black. It's possible the expression for this gene is kicking in. Your betta is a veiltail and his genetic history is definitely a mystery since in this breed "anything goes". For all we know, his breeder intended him to be an extended red, but he may carry the red-wash gene or other genetic impurities that have lightened his colour with age and given rise to pigment spots. Pigment spots like yours are normal. It's particularly common in red bettas.
Bettas are comfortable with water even up to 84F so don't worry about him overheating.