I get asked
about this a lot, so I thought I would clarify a few things…
“Why do the nations’ eye colors keep changing?”
Hima
directly answers this question on his blog by stating that there’s “sufficient
freedom” regarding the eye colors of the nations. This would include sometimes
adding light brownish or greenish tints.
Although,
this obviously doesn’t explain why Sweden and Finland have solid brown eyes (and darker hair) in the first episode of
the anime. Regardless, that’s an animation inconsistency, not a canon one.
Likewise,
if you’re wondering why eye colors go from blue to violet to green, as seen
with the Nordics, there’s actually a justified reason for this.
Hima
provided a chart years ago revealing the different range of hues/mixes that each
nation’s eye and hair colors can assume.
“I tried to put every character’s hair and eye color in order. Being that this is something like an approximation, they do things like change in illustrations. But it’s like this, and I hope it’s good and easily understandable.”
That said,
there isn’t really one correct eye color for the nations, nor is there one
correct hair color; it’ll always differ slightly.
Make sense
now?
You can find the chart here:
Ellawritesficssometimes 
