I agree.The saying is a bit old-fashioned, in my experience. And I've always heard it as "green around the gills."
We need to know where this example came from.It would be helpful if you would provide the source - which website?
If a person looks blue around the gills, they look unwell or sick.
"You should sit down. You look a bit blue around the gills."
Thank you. I am surprised. I would expect the principal entry to be green around the gills and the variants to be blue and pale.
The website says "also green or pale around the gills" but they have listed it under "blue" with an example using probably for the sole reason that "blue" is alphabetically first. I think that's quite misleading as "green" seems to be much more commonly used while "blue" is the least used of the three. It's nice to know that you might see "blue" or "pale", but you would be better off using "green".I see that it came from a definitions website where the expression is defined as: