In 3e, when I was most on top of the lore, Tieflings were tainted by a infernal bloodline, it didn't make them inherently evil, it only meant they had to deal, more than their base race, with the inclinations of that bloodline, I remember in Dragon mag and maybe elsewhere these things were expanded on a little for all the different flavors of plane-touched templates. In 5e, they've all been 'claimed' by one or two bloodlines or something like that, sure, but my question was really about how alignment affects the physical aspects of certain races. Similar to this, I learned (or maybe relearned) in the EA that Lolthsworn Drows' eyes turn red, is that from birth? Do they change when you renounce Lolth?
I remember in 3e that in the MM tieflings and aasimar weren't alignment restricted, looking up 3.5 they're "usually evil/good (any)". Of course what I remember most about them is the artwork, I've wanted to make that mustachioed aasimar in a game for ages. WotR came close.
Having physical attributes completely at odds with your personality or out of your direct control is an interesting wrinkle to a race/character.
