Mostly fluffy, but there will be angst!
A is for Aura
The first time that he saw the colors, he thought that he was going crazy. It was bad enough that that portal accident had given him strange and terrifying powers, but now he was hallucinating because of it too!
It wasn't until much later that he understood fully what had happened.
That his mother had turned dark red like that with those long reaching tentacles because she was angry, not because she was a ghost. That his sister had turned light lavender when she went to comfort him after he screamed in surprise and ran from the room and up into the Ops Center as fast as he could. That his father had shone dark blue with confusion, then brightened to orange with excitement when Danny had let him babble on about ghosts.
When Frostbite had explained that some ghosts could see aura's, it all clicked into place. The peculiar shimmers that were added to the colors when someone was overshadowed, although they were practically undetectable on anybody except for when Spectra was doing the possessing-she made the people turn dark black with slight stripes of red and deep purple all over.
Sam, Jazz, and Tucker were the first people that he told, and they all had different reactions. Sam was pleased, and made him tell her if her emotions were different because she was goth (the weren't). Tucker nodded and pointed to a series of hot girls, and had Danny try to use his powers to make them ask him out and feel strong feelings off affection for him (Danny refused). Jazz pointed out that the power could be an excellent therapeutic tool, and wandered off while muttering to herself about it.
When the Disasteriod happened, and he owned up to his parents-and the world-about his powers and his ghostly alter-ego, he also told them about the auras.
His dad started working on an invention called "The Specter Sighter" ("That's a terrible name, dad."
"Don't argue with greatness, Danny boy!")
that worked in a similar fashion to his ability to see the auras.
And suddenly, his family could see like he could, and Danny's world was tinted the lovely hues of the happiness spectrum.