High Elves have skins specially made for them along with Hair Colors that Blood Elves do not have access too.
They share 1 skin tone.
Model bugs or special case characters. You can’t pick them on the character screen so they are not a feature of Blood Elves in anycase.
Fun fact, they relabeled High Elf models so they would not accidentally get Gold Eyes and so Blood Elf NPCs would not randomly get Blue/Purple Eyes in BFA.
Lots of High Elves have purple eyes. Mostly Dalaran ones seemingly.
Vereesa Windrunner is a good example of a White Hair Color unavailable to Blood Elves.
And Blood Elves can not naturally have Blue Hair.
Yes they did. Go read the lore.
Why do you think they have Green Eyes and Redder Skin? lol
Blood Elves and High Elves have been separated for 30 years for some groups and 3000ish thousand years for others. More than enough time to develop differences.
Especially with the Blood Elves rampant abuse of various magics and the fact they had 91% or more of their population removed. Possibly eliminating many traits from their population.