Ah sorry my mistake. Should have been 6 red food...
But as you said, she has to starve, even if there is enough food of one color.
No, that's different.
In Primordial Soup amoebas can purchase "gene cards" that improve the abilities of all of a player's amoebas. Many of the gene cards combine abilities in interesting ways. If you have cards like Substitution, Frugality and even Parasitism, they can combine to let your amoeba survive in areas entirely of one colour. Of course Struggle for Survival and Aggression let you eat other amoeba.