This is a walkthrough of Older. This guide will tell you where to find the effects in Older. Spoilers ahead!
Wheel- Go to the blue door and find a small room with a moving wheel. Interact with it to recieve the effect.
Pitchfork- Go to the door with bloodstains on it and find a bleeding thing with a pitchfork in it. Interact with the right side of it to recieve the effect.
Silver Hair- Go to the door with bloodstains on it and interact with the green trashcan. The trashcan should take you to a colorful area with pink grass. Go right and interact wih the second monochrome door. Once you're inside, interact with the chalkboard to recieve the effect.
Wire- Go to the blue door and interact with a monochrome door. You'll be inside a blue maze. Find the rectangular NPC and you'll be in a desert with gas tanks. Interact with the tank with a bloody window. You'll then be in a black map with more gas tanks. Find a tank with a mouth for a window to recieve the effect.
Once you find all of the effects, interact with your door in the real world to view the ending.