I'm puzzled. What does IsoE mean? According to the first portugese - english dictionary I googled, the protugese for "red" is "vermelho" and green is "verde".
Incidentally, here's a nice picture, shamlessly hotlinked from Wikipedia. It's a lot clearer when you see how much of the land is built up ...
it's "Encarnado" or better "cor encarnada" meaning red colour.
Vermelho means red indeed but for some reason (?) navigational marks use the encarnado word. Maybe they did not want to create confusion among Verde and Vermelho ?