Was it ever said that the arcane makes an elf eye blue? Then why did pre-scourge elves have variety of eye colors?
Holy and fel energies do affect elves’ eye color however. Light magic doesn’t cleanse, it also corrupts like any other power from the cosmos. We’re not expecting Xe’ra turning Illidan into a regular Night Elf. No one among the sunwell-sustained, non-warlock elves should have blue eyes
They…what? You know they’ve used a different voice over for alliance “high elf” NPCs since TBC? It’s snippets form the night elf ones as far as I recall.
Blood elf voice overs are very much unique to Blood elf NPCs…
Waiting for Explorer’s League High Elves
that… was the point of clearing sunwell.
It’s like you people woke up and thought:
“I’m going to roleplay as a brick wall today”.
As I understand it.
High Elves do actually have a variety of eyecolours similar to humans, it is just that the magic gives them that fiery glow. I also understand, that the High Elven rangers, being less magically inclined, would actually not have that glow - but appearantly blizzard can not make that distinction between classes on the same race.
We see multiple times that the light does cleanse fel. Yes, it also “corrupts” but blizzard already did put precedence for how the Sunwell currently works, with the golden eyes. Only priests and paladins are supposed to have the golden eyes, that is why we will usually only see Blood Elf NPCs of those classes with golden eyes.
Aka, these classes pull from the light energies of the Sunwell. This creates the implication, that pulling from the arcane energies would make the glow blue.
In the shadow of the sun, also mentions that the elves are exposed to both energies regardless. Lor’themar stating that the Sunwell’s magic is different, and it would take some elves to get used to it.
Actually yes…it was. That wasn’t necessarily the only color but it was the most common.
It was said in interviews that high elves are like a sponge to magical energy, and the sunwell once being pure arcane is what caused the blue. This was later referenced again in other stories such as Valeera Sanguinar where her eyes turned purple after absorbing magic of another source. High elves/blood elves’ eyes basically reflect the most common magical source they are linked to/using/surrounded by.
As for your second reference, I think even you know that trying to use an argument for lore based around the idea of limitation of gameplay cosmetics and mechanics of the past, or even change in lore Writing from WC3 (which there was A LOT), isn’t a very fair or logical argument.
I’m assuming for pre-scourge you’re referring to WC3? Yes the high elves/blood elves had multiple eye colors, some for holy, some for arcane, etc. The green we later were told was a teaser for where they wanted the direction of the story to go for TBC.
This all said, I’ve addressed the points above about their eye glow color and history and the general idea of using WC3 models as reference or otherwise. 
Their conflicts are what made this harder to explain the differences even with the amount of elves hanging around the alliance including Valeera or Arator.
Pretty sure I may have seen a void elf in there yep
Most, if not all the BEs kicked the Fel to the curb once the Sunwell was restored. So Blue and Gold eyes would start becoming more common.
This is pretty true.
The story tells us that all fel influence was removed and any using such stopped. It does mention some “refusing to give up the power they have now gained”, whether from pride or fear (which part of me thinks may majority be the warlocks in their society).
It does seem fitting for green glow to become a rarity.
Blood Elves are High Elves.
A vote amongst the Kirin Tor council was made (during the Legion expansion) to allow the Sunreavers back into Dalaran, under parole. Jaina left the city, and the Kirin Tor council, in protest of the vote.
Due to Aethas Sunreaver’s efforts against the Legion, the Blood Elves are now in good standing once more, so there will be plenty of blue-, gold- and green-eyed elves in Dalaran now. Perhaps even purple-eyed, now that the Ren’dorei are part of the Alliance?
My understanding is that the gold eyes are reserved for Blood Elven paladins and priests. So probably no gold eyes in Dalaran.
Perhaps not as mages, or as members of the Kirin Tor, if membership is exclusive to casters of the arcane…but there are quite a few non-mages living in the city. I agree that the numbers would be small, but not utterly absent.
I’m sorry if that seems a bit pedantic, but I can’t help myself sometimes… 
While all Blood Elves are High Elves not all High Elves are Blood Elves.
Glory to the Sin’dorei is High Elf which is also used by Blood Elves because they are High Elves.
Legion actually added a new generic silver covenant voice set for npcs like courier larkspur too
Technically their “eyes” are not blue, they are just glowing blue because of the type of magic they use (which has been Blizz lore for a long time and why Blood Elves eyes were green when they consumed Fel energy and now Yellow from the Light Well magic).
That we are.
Void Elves are also Blood Elves, who are also High Elves.
But to the OP yea blue are gold are the predominant eye colours now (lore wise)
I think they’re just colored contacts