Fun things:

Comparing Keith and Shiro’s eye colors, Keith has noticeably purple eyes, even when they’re in the same lighting:

This is from the same scene, when they’re standing outside talking in s1e1.

Now, outside of purple being the commonly associated Galra Color ™, it’s an unusual eye color for humans. Pidge has hazel eyes, Lance has blue eyes, Hunk has dark brown eyes, and Shiro’s are gray- we don’t exactly have a plethora of unusual eye colors here. 

The other fun thing?

He seems to get it from his dad.

The only scene we’ve seen his dad so far in has heavy orange tint, but if we take what we know here ^ in neutral lighting:

The colors used are almost exactly the same. Dad Kogane’s are a little more desaturated which might suggest his eyes are a lighter shade of purple- the “bright” section of the eye is also wider. (for maximum clarity, I only color selected on the eye that’s in direct light here, not the shadowed one, because there’s no shadow on Keith’s eyes)

I’d love to test this by trying to neutralize the orange, but, I have no idea how to do that. If anybody knows and wants to help out, I’d be much obliged.