Work Text:
“It is a spectrum,” Castiel explains, when Dean asks about it.
Castiel is his best friend, his lover, his everything, so when the diagnosis comes — so late in his life — Dean has a lot of questions, because he wants to understand.
So Cas explains to him that while it is a spectrum, it doesn’t have a low and a high and a middle — it’s more like the color spectrum. There’s an infinity of possible colors, all different, all autistic, and beautiful all the same.
Dean tells him that Cas is, and always will be, his favourite color in the world.