How is the term "blue" often interpreted when describing poultry eye color in this context?

Answer

A pale, icy shade, sometimes appearing as washed-out greyish-blue

The text specifies that "blue" in poultry often refers to a pale, icy shade rather than a vibrant, true blue, sometimes appearing as a washed-out greyish-blue.

How is the term "blue" often interpreted when describing poultry eye color in this context?
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