Genesis 25:30 says:
... הַלְעִיטֵנִי נָא מִן הָאָדֹם הָאָדֹם הַזֶּה ...
... "Pour into [me] some of this red, red [pottage] ..."
Why did Eisav feel the need to say "red" twice?
In a midrash: Why did he repeat? Esav found Yaakov preparing lentils for his father in a dish, and told him "feed me" [=hal'iteni na min haadom]. He said, "wait, I'll prepare you another dish. I prepared this one for my father and don't want to cancel my mitzva. But if you're willing to sell your birthright, I'll give you my father's dish, which I'm allowed to do in order to purchase a mitzva. Otherwise, wait". And Esav replied, "I want only this dish [=haadom haze], for it's fat and good". And that's why he said hal'iteni na min haadom haadom haze: "I want this one, as it's fat, and will sell you the birthright".
— Tol'dos Yitzchak, by Rav Yitzchak Karo (uncle of the Bes Yosef), in my own free translation
I think it just shows Eisav's infatuation with the food. The redness is was draws him to it. So the pasuk is describing his words in a way for us to understand his thoughts, i.e. "The red, red stuff," all I care about is how appetizing and juicy it looks.
My thoughts was that it reminds me of the 'two bloods' of pesach and brit milah. I asked a scholar if this was the connection and he said yes. I am still pondering the deeper implications of this.