ALSO I don’t know if I’ve ever discussed this on here but oh boy let me ramble
I 100% believe Touya’s flames where the color red/orange has a child but didn’t start turning blue until he was at Sekoto’s peak that one night realizing he could make his flames more powerful
he tells us how his quirk is directly connected to his emotions, we all know what happened, his emotions overtook him and was unable to control his fire
his fire didn’t turn fully blue until after his “death”
which is another reason why no one ever recognized him, they had never seen someone with a blue fire quirk
this all can tie into the theory that this is part of some kind of “phoenix” quirk, his body went through a rebirth which is how he survived but also this was just the next evolution of his flame power
there’s also some evidence that since the first war arc Dabi’s flames are now white (they are drawn slightly different than before) and hotter than ever, and this could be him entering a new rebirth (if his quirk is phoenix related)
there’s also the symbolism of his hair turning fully white and him choosing to wear all white clothes
where he’s at now parallels perfectly to Sekoto’s peak with how his dad is neglecting him once again, his emotions are overtaking him again, and he’s completely over taking himself and everything around him