Which color collar is used for an amplifier connection on a speaker add-in card?

The correct answer is lime, which is used for amplifier connections on a speaker add-in card. In audio equipment, different colors are designated to signify specific functions, primarily to help users easily identify where to connect different types of audio devices. The lime color specifically indicates a line-level output intended for connection to the amplifier, ensuring that the audio signal is correctly routed to the right output for optimal performance. This distinction is important for setting up sound systems accurately, as each color corresponds to a different type of signal or function, facilitating proper connection and functionality throughout the audio system.