Red Eyes, Take Warning

An easy way to tell a villainous (or sinister) character apart from the protagonists, other than giving them a Red Right Hand, is making their eyes red. If they don't start out evil, there's a chance they become so over time or perform full-blown Face–Heel Turn. It's not the same thing as the "red eye" phenomenon in photos, but if cameras could detect evil, or danger these would be the first people they'd catch. Even those who aren't truly evil or dangerous are often thought to be so by characters In-Universe. In the progressive algorithm of "Uh-Oh" Eyes we have: Supernatural Gold Eyes < Red Eyes, Take Warning < Hellish Pupils < Glowing Eyes of Doom Those with glowing red eyes are almost without exception thoroughly evil or, at least, on a Roaring Rampage of Revenge or filled with Unstoppable Rage. The "almost" section goes to those whose red eyes serve as a marker for their Elemental Powers, since Fire Is Red typically or they’re Playing with Fire. Albino characters with red eyes may suffer from this association with evil; see Albinos Are Freaks. A subtrope of Technicolor Eyes. Compare Glamour Failure, Red Is Violent, Creepy Blue Eyes. Contrast Red Is Heroic. Not to be confused with the film Red Eye or the liquor, or with late-night airline flights. Sometimes a part of Burning with Anger, and thus a harbinger of wrath from the Seven Deadly Sins wrath. It should be noted that this trope is NOT just for characters who have eyes of this color, but when the color actually indicates the character is evil or dangerous, or has the Face of a Thug because of their eye color. Please do not add characters who just happen to have eyes of this color without the proper reason behind it.