It's impossible to say what color wire goes in "COM" without more context! "COM" can refer to different things in different situations.

Here's why you need more information:

* Electrical wiring: "COM" often refers to the common terminal in a switch, outlet, or device. The color of the common wire varies widely depending on the location and wiring code. In the US, it's often black but could also be red or blue. In Europe, it's usually blue.

* Electronics: "COM" can also refer to a common terminal on a circuit board or in a device's connection. Again, the color of the wire can vary greatly depending on the manufacturer and design.

* Other contexts: "COM" might have other meanings.

To give you the right answer, please tell me:

* What kind of device are you working with? (e.g., a light switch, a computer, a power supply, etc.)

* Where is the "COM" terminal located? (e.g., on a circuit board, on a switch, etc.)

* What country are you in? (Wiring codes vary internationally)

Once you provide this information, I can tell you the color of the wire that should be connected to the "COM" terminal.