If you have multiple dogs, different colors of collar key colors CANNOT be mixed with a single door. For example, you cannot use a red key and a black key with the same door.
Any color key will work with any door, it is just a matter of programming the door for that particular color key. For example if you have a door with a red dot, it can be programmed to work with a black key. To program the door, simply remove the power (either wall outlet, batteries or both) from the door. Wait 30 seconds and then power the door. The first key, regardless of color, that you hold in front of the door will be the color that works with the door. The key about approximately 3/4" long, 1/4" wide and weighs less than one ounce.
IMPORTANT NOTE: For Staywell Infra Red Electronic Dog Doors only, will not work with STAYWELL-400 Doors.