See also Audio stuff for sizes, and such.
3.5mm sound plug colors ∞
What do all the 3.5 mm jacks on the back of your motherboard mean?
|Blue||Input: line level (line in)|
|Lime||Output: line out, front speakers, headphones|
|Brown||Output: 'Right-to-left speaker' (Is this rear surround speakers?)|
|Gold||MIDI/game port (Joystick)|