Wrinkly Door

From the Super Mario Wiki

Wrinkly Doors is were the ghost of Wrinkly Kong rests, there are doors outside the entrance of all levels in Donkey Kong 64(except Hideout Helm), if a Kong gets in front of the door, Wrinkly will come out an tell them a tip of were to find a Golden Banana, depending outside of what level she is. There are five different colors of doors: yellow, red, blue, purple and green, each color represents for which kong is the tip.