In this puzzle, there are wires connecting two boxes and the room is dark. There are 4 wires coming out of the box on the left with each having a different colored base. You have to follow the lines from the colors on the left box to the right box.
Top left: BlueTop right: PinkBottom left: YellowBottom right: Red
Once you do this, the lights will be turned on. Grab the key and escape this level.