Why are Aerith's eyes green?

I know that Cloud has green eyes because of his exposure to mako, since he was in Shinra's SOLDIER, First Class rank. However, I also noticed that Aerith has green eyes.

Does this have something to do with Aerith being an ancient, and is it somehow associated with the Earth's lifestream? Or do her green eyes have no correlation to lifestream and mako energy?

Wikipedia says that her eyes are green to "symbolize nature," but there is no source to back up this claim. Does anyone have authoritative sources to back this up, or some other explanation?

Solution 1:

The mako injection given to SOLDIER members doesn't turn their eyes a different color. What it does is add a green glow to their eyes, which is generally seen as a SOLDIER's trademark and makes them more easily identifiable.

Prior to the mako exposure, Cloud had blue eyes. The Final Fantasy VII Remake puts a lot more emphasis in the green glow, but you can see Cloud's blues eyes with the green glow a lot more clearly in the Final Fantasy VII: Advent Children movie

As for Aerith's eyes, her eye color is a solid green. Her green eyes are shown in various continuities of Final Fantasy VII. The screenshot on the left is from The Final Fantasy VII Remake and the screenshot on the right is from Final Fantasy VII: Crisis Core.

Since the the wiki quote for her eyes symbolizing nature is un-sourced, it's likely the information is based on urban legends indicating your eye color saying things about who you are (one blog I read indicated green eyes go along with nature and other stuff).

It's possible her eyes may have gradually turned green over a long period of time. If I remember correctly, very little of Aerith's childhood is shown. So it's hard to say what her eye color is at a young age.

The only shown case of Aerith being exposed to Mako is during the opening sequence, and she is looking at a broken valve that is radiating mako. We do not know if this was a multiple occurrence or if was a one-time exposure.

[Minor spoilers below]

It's also possible she may have had exposure

with her long time spent at the Sector 5 Church. In Final Fantasy VII: Advent Children movie, it is shown that the Lifestream (which, in liquid state, forms Mako) flows beneath this church; which is why flowers are able to grow there.