2007 chevy colorado cd/am/fm wiring

Dual makes a device called the iplug which is just a mini jack input with male RCA outputs (or you could even go to radioshack and simply buy a minijack input to male RCA output adapter).  However, obviously in order to hook up one of said devices you will need RCA inputs.  If your factory stereo has an input in the back for an auxillary device such as XM radio or a CD changer then you can more than likely purchase a device (Peripheral makes such devices) which would convert that proprietary GM port into universal RCA inputs.  If your stereo DOES NOT have such an input, then you're probably going to have to buy an aftermarket stereo with a minijack input built into it (honestly, you'd spend about the same to get an entry-level aftermarket head unit that you would to do what I described above).