Double Knit Cables

I have looked aroud for double knitting resources on the web and they are relativly few.

I was wondering if any would could tell me about double knitting something that is NOT stockingnet stich on both sides? Must both sides be exact reverses of eachother? Or is the color all that needs to be reversed? What are the restrictions on the relationships between colors on oposite sides? It seems to be that you can’t knit with the same yarn on both sides but other wise it should be okay.

does any one have any ideas/ sugestions on how to make cables go thourgh the fabric?

Thank you in advance for your help.
Aloha
Robert