Input and output jacks on the back of my computer

I have a Dell Dimension L667r computer, and I'm trying to figure out which jack on the rear of the computer should be used to for an analog input (from a tape recorder).  I have studied my manual ("Reference and Troubleshooting Guide") and find diagrams on pages 2-6 and 2-7, but my computer doesn't look like that.  The three vertically aligned jacks shown don't exist on my computer.  Instead below the fan there is a horizontal row of five jacks with colors as follows (from left to right facing back): black, light green (output to subwoofer and speakers), light red (apparently an input from a microphone, although I'm not certain about that), light blue, then the vertical words "digital out", and light yellow.  Is there a diagram available that  shows the purpose of all the jacks and plugs on the back of the computer?