Speaker cables of cooper, or silver :Pros/Cons

What's cooper? :)

Depends on the rest of your system, and the frequency response of your ears. Copper is darker, so it can be used to good effect with a system that is bright or fatiguing. Silver is brighter, so use it with a laid-back system, of if you want more air. Also, since the human ear is unique like a fingerprint, season to taste. But in either case, use OCC copper or silver only.

In general, because there is no hard and fast rule as design implementation also comes into play, copper will sound warmer and richer and silver will sound more revealing and transparent. Gold is also warm, like copper, but captures a bit more harmonic textures. Many companies will try to combine some of these attributes by combining them, ie. silver clad copper, gold clad silver, gold clad copper, etc. From my experiences, straight silver is a bit too bright for my system/tastes. I do find that I like silver clad copper and/or gold clad silver cables though. I have also heard systems where pure silver worked very well, generally in a system with warm speakers and electronic components.

I have not listened to platinum conductors, though I have heard carbon fiber conductors, which have many of the characteristics on copper IMHO.