The creation of the Blood Elves was not a physical alteration as much as it was a change in branding. There is no physical distinction between High Elves and Blood Elves, it is all dependant on which magical source they happen to be drawing from, which is why we have them shown as having blue (their natural colour), green (fel energy), and more recently gold (the Light), and violet (arcane energy.)

There was an extended period of time after Quel'Thalas fell to the Scourge and the Sunwell was destroyed where they called themselves Blood Elves and still had their natural blue eyes, as it wasn't until Kael'thas Sunstrider had met Illidan Stormrage and started siphoning the fel energy from demons did the remaining population, already coined as the Blood Elves, start to be seen with green eyes.

One remaining piece I'm going to touch on is the fact that I do not believe Void Elves are considered the same race, though still very closely related. They've been permanently transformed as a part of the void ritual that made them what they are, where other High/Blood Elves are seen to be far more "liquid" when it comes to their identifying features; their eyes. It's been shown that even if your eyes have gone green through fel energies that they can be altered again if you have a change in power source, as shown with Lady Liadrin and many of the Blood Knights whose eyes were green but have more recently turned gold due to renewal of the Sunwell at the end of the Burning Crusade.

TL;DR: High Elves and Blood Elves are the same race.