Red is a humanoid with large, wide eyes and a round red colored head. Unlike the other Rainbow Friends, his body is similar to that of a Robloxian. He is seen wearing a lab coat over a black business suit, a red undershirt, black neck tie, and black gloves. It is unknown whether he is a monster or a disguised human. Red is a psychopath and a sociopath, cruel, manipulative, violent, smart, and sadistic as he shows no empathy towards the player. He is by far the most intelligent of the Rainbow Friends and the only one who actually speaks. He is a skilled manipulator and liar; after he guides the player to restore power to the facility on Night 4, he tells them to stay in the facility for a goodbye party for one more night instead of letting them go immediately, which put them in more danger.

Green is a tall, lanky green monster with plastic googly eyes and jagged teeth. His body is mostly cylindrical. He stands upright, sporting extremely long, flexible arms. He has three fingers on each hand and two short legs. Green's jaws can hinge open incredibly wide, revealing a long red tongue. His body is covered in a mottled texture, giving it the appearance of fur or nylon. Green is completely blind, thus is unable to chase players. Rather, he walks along a set path, stopping at predetermined points to assess his surroundings. After feeling the immediate area with his arms and hands, he will pause for a few seconds before continuing along his route. He may decide to backtrack, but he never diverges from this path. If a player is near Green, he may open his mouth and scream, emitting the sound of a distorted party horn. This dosen't harm the Player though. Despite being unable to see, Green will immediately grab a player upon touching them, even if they are hiding in a box.

Blue is a large, heavy royal blue[1] monster. Fittingly, he wears a yellow crown on his head. His arms are long and bulky when compared to his short, stubby legs. Pale blue drool hangs from the side of his mouth. Blue's right eye is round and dilated, however, the eye on his left has seemingly been replaced with a white button. In-game, he appears hunchbacked, walking with poor posture.

Orange is a short, scrawny monster, resembling a Baryonyx. He is characterized by his bright orange skin, bulging eyes, and rows of sharp, conical teeth lining his triangular jaws. His vertical pupils will sometimes look in opposite directions. He appears upright when standing, balancing on two spindly legs with his three-clawed hands reaching forwards. His twig-like body ends with a stubby tail.

The Lookies are small, ball-shaped characters with huge eyes. (No mouth)