In "Sonic the Hedgehog", what colour is Knuckles?

Knuckles the Echidna is a character from Sega's "Sonic the Hedgehog" series. He is a red anthropomorphic short-beaked echidna who is Sonic's best friend and former rival. Determined and serious, but sometimes gullible, he punches enemies with brute force. He serves as the guardian of the Master Emerald, a huge gemstone that controls the series's integral Chaos Emeralds, and is the last living member of his tribe, the Knuckles Clan.

Knuckles debuted as an antagonist in "Sonic the Hedgehog 3" (1994) after Doctor Eggman tricks him into opposing Sonic and Tails. He first became a playable protagonist in "Sonic & Knuckles" later that year; after initially opposing Sonic once again, he forms an alliance with him after learning of Doctor Eggman's trickery. Since then, he has appeared in dozens of playable and non-playable roles, as well as in several series of comic books, Western animated television, Japanese anime, the "Sonic the Hedgehog 2" feature film and its upcoming sequel.