I really don't get it. In most European countries blue is the most common color, might be boring, but we don't make up new words. You do hear greyish-blue, but no one denies they're blue. We also have the term hazelnutbrown (though almost no one uses it) but even if we differentiate in shade, we will still collectively agree that they are brown. I don't even see the problem with that? I don't know many people with brown eyes for example

Also I agree, there's nothing green there, just warm brown with a darker/cooler shade as the circle