I just moved into a brand new house and I found I dont have a single electronic that is black except for my 10 yr old speakers.
I want to throw it away Sooo much.

I think black (especially ABS plastic) is just plain ugly and yells ! Cheap !
The problem is, black "sticks out"; it's an obstrusive color matched to interior colors like white, beige & brown.
Just think about the wires for your entertainment system against hardwood floor/wall, wouldn't they look much more discrete if silver/white, but not black?

Silver in comparison blends into environment much better, relects light and "shines".
For this reason, many manufacturers choose to color their appliances silver, or use reflective materials for dark colors(polycarbonate coating). Eg, Ipod, PS3, Stainless steel appliances etc.

Conciousness in design and improvement in manufacturing techniques results in the move, not jsut from black to silver, but in general, from dull to shiny.
Silver plastic just happens to be the best solution because it is cheap and effective.