Red (Spanish for “network; net”) comes from the Latin rete, meaning “net.”
From the same root, we get the English… retina. How? What does your eye have to do with a net?
Well, if you look deeply into someone’s eye, their retina turns out to be a very tight network of blood vessels. And thus, your retina really is a… red (Spanish sense)!
You can see that the r‑d of red maps to the r‑t of retina.