So i pretty much added color to the mesh however i noticed the following:
in Edit Mode:

in Object Mode:

Same thing happens with the other eye

from my understanding, it has to do with the subdivision modifier...but how do i go in solving it?
Hi Jonathan!
That has indeed to do with the Subsurf Modifier.
It looks to me that you have a very small bevel on that edge with 1 segment, something like this (exaggerated):

Which subdivides like this:

Because it has only 1 segment, it also has only 1 color.
You will need another edge loop:

Which subdivided looks like this:

Then assign the right material here:

And you get this when subdivided:

Or in Object Mode, with Smooth Shading:

It's a bit difficult to explain, but I hope it is clear from the pictures.